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feat: add new ip modules
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@@ -0,0 +1,107 @@
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/* Simple 32-bit counter-timer for ravenna. */
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module counter_timer (
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input resetn,
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input clkin,
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input [3:0] reg_val_we,
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input [31:0] reg_val_di,
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output [31:0] reg_val_do,
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input reg_cfg_we,
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input [31:0] reg_cfg_di,
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output [31:0] reg_cfg_do,
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input [3:0] reg_dat_we,
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input [31:0] reg_dat_di,
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output [31:0] reg_dat_do,
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output reg irq_out
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);
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reg [31:0] value_cur;
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reg [31:0] value_reset;
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//reg irq_out;
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reg enable; // Enable (start) the counter/timer
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reg oneshot; // Set oneshot (1) mode or continuous (0) mode
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reg updown; // Count up (1) or down (0)
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reg irq_ena; // Enable interrupt on timeout
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// Configuration register
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assign reg_cfg_do = {28'd0, irq_ena, updown, oneshot, enable};
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always @(posedge clkin or negedge resetn) begin
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if (resetn == 1'b0) begin
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enable <= 1'b0;
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oneshot <= 1'b0;
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updown <= 1'b0;
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irq_ena <= 1'b0;
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end else begin
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if (reg_cfg_we) begin
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enable <= reg_cfg_di[0];
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oneshot <= reg_cfg_di[1];
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updown <= reg_cfg_di[2];
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irq_ena <= reg_cfg_di[3];
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end
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end
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end
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// Counter/timer reset value register
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assign reg_val_do = value_reset;
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always @(posedge clkin or negedge resetn) begin
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if (resetn == 1'b0) begin
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value_reset <= 32'd0;
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end else begin
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if (reg_val_we[3]) value_reset <= reg_val_di[31:24];
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if (reg_val_we[2]) value_reset <= reg_val_di[23:16];
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if (reg_val_we[1]) value_reset <= reg_val_di[15:8];
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if (reg_val_we[0]) value_reset <= reg_val_di[7:0];
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end
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end
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assign reg_dat_do = value_cur;
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// Counter/timer current value register and timer implementation
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always @(posedge clkin or negedge resetn) begin
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if (resetn == 1'b0) begin
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value_cur <= 32'd0;
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irq_out <= 1'b0;
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end else begin
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if (reg_dat_we != 4'b0000) begin
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if (reg_dat_we[3] == 1'b1) value_cur[31:24] <= reg_dat_di[31:24];
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if (reg_dat_we[2] == 1'b1) value_cur[23:16] <= reg_dat_di[23:16];
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if (reg_dat_we[1] == 1'b1) value_cur[15:8] <= reg_dat_di[15:8];
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if (reg_dat_we[0] == 1'b1) value_cur[7:0] <= reg_dat_di[7:0];
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end else if (enable == 1'b1) begin
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if (updown == 1'b1) begin
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if (value_cur == value_reset) begin
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if (oneshot != 1'b1) begin
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value_cur <= 32'd0;
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end
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irq_out <= irq_ena;
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end else begin
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value_cur <= value_cur + 1; // count up
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irq_out <= 1'b0;
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end
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end else begin
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if (value_cur == 32'd0) begin
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if (oneshot != 1'b1) begin
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value_cur <= value_reset;
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end
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irq_out <= irq_ena;
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end else begin
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value_cur <= value_cur - 1; // count down
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irq_out <= 1'b0;
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end
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end
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end else begin
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irq_out <= 1'b0;
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end
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end
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end
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endmodule
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@@ -0,0 +1,542 @@
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/////////////////////////////////////////////////////////////////////
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//// ////
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//// WISHBONE rev.B2 compliant I2C Master bit-controller ////
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//// ////
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//// ////
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//// Author: Richard Herveille ////
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//// richard@asics.ws ////
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//// www.asics.ws ////
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//// ////
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//// Downloaded from: http://www.opencores.org/projects/i2c/ ////
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//// ////
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/////////////////////////////////////////////////////////////////////
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//// ////
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//// Copyright (C) 2001 Richard Herveille ////
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//// richard@asics.ws ////
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//// ////
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//// This source file may be used and distributed without ////
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//// restriction provided that this copyright statement is not ////
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//// removed from the file and that any derivative work contains ////
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//// the original copyright notice and the associated disclaimer.////
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//// ////
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//// THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY ////
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//// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED ////
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//// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS ////
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//// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR ////
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//// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, ////
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//// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES ////
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//// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE ////
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//// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR ////
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//// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF ////
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//// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ////
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//// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT ////
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//// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE ////
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//// POSSIBILITY OF SUCH DAMAGE. ////
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//// ////
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/////////////////////////////////////////////////////////////////////
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// CVS Log
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//
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// $Id: i2c_master_bit_ctrl.v,v 1.14 2009-01-20 10:25:29 rherveille Exp $
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//
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// $Date: 2009-01-20 10:25:29 $
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// $Revision: 1.14 $
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// $Author: rherveille $
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// $Locker: $
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// $State: Exp $
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//
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// Change History:
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// $Log: $
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// Revision 1.14 2009/01/20 10:25:29 rherveille
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// Added clock synchronization logic
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// Fixed slave_wait signal
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//
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// Revision 1.13 2009/01/19 20:29:26 rherveille
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// Fixed cr[0] register width
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// Fixed ! usage instead of ~
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// Fixed bit controller parameter width to 18bits
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//
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// Revision 1.12 2006/09/04 09:08:13 rherveille
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// fixed short scl high pulse after clock stretch
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// fixed slave model not returning correct '(n)ack' signal
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//
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// Revision 1.11 2004/05/07 11:02:26 rherveille
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// Fixed a bug where the core would signal an arbitration lost (AL bit set), when another master controls the bus and the other master generates a STOP bit.
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//
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// Revision 1.10 2003/08/09 07:01:33 rherveille
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// Fixed a bug in the Arbitration Lost generation caused by delay on the (external) sda line.
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// Fixed a potential bug in the byte controller's host-acknowledge generation.
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//
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// Revision 1.9 2003/03/10 14:26:37 rherveille
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// Fixed cmd_ack generation item (no bug).
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//
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// Revision 1.8 2003/02/05 00:06:10 rherveille
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// Fixed a bug where the core would trigger an erroneous 'arbitration lost' interrupt after being reset, when the reset pulse width < 3 clk cycles.
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//
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// Revision 1.7 2002/12/26 16:05:12 rherveille
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// Small code simplifications
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//
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// Revision 1.6 2002/12/26 15:02:32 rherveille
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// Core is now a Multimaster I2C controller
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//
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// Revision 1.5 2002/11/30 22:24:40 rherveille
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// Cleaned up code
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//
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// Revision 1.4 2002/10/30 18:10:07 rherveille
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// Fixed some reported minor start/stop generation timing issuess.
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//
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// Revision 1.3 2002/06/15 07:37:03 rherveille
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// Fixed a small timing bug in the bit controller.\nAdded verilog simulation environment.
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//
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// Revision 1.2 2001/11/05 11:59:25 rherveille
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// Fixed wb_ack_o generation bug.
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// Fixed bug in the byte_controller statemachine.
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// Added headers.
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//
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//
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/////////////////////////////////////
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// Bit controller section
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/////////////////////////////////////
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//
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// Translate simple commands into SCL/SDA transitions
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// Each command has 5 states, A/B/C/D/idle
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//
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// start: SCL ~~~~~~~~~~\____
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// SDA ~~~~~~~~\______
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// x | A | B | C | D | i
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//
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// repstart SCL ____/~~~~\___
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// SDA __/~~~\______
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// x | A | B | C | D | i
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//
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// stop SCL ____/~~~~~~~~
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// SDA ==\____/~~~~~
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// x | A | B | C | D | i
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//
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//- write SCL ____/~~~~\____
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// SDA ==X=========X=
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// x | A | B | C | D | i
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//
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//- read SCL ____/~~~~\____
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// SDA XXXX=====XXXX
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// x | A | B | C | D | i
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//
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// Timing: Normal mode Fast mode
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///////////////////////////////////////////////////////////////////////
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// Fscl 100KHz 400KHz
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// Th_scl 4.0us 0.6us High period of SCL
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// Tl_scl 4.7us 1.3us Low period of SCL
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// Tsu:sta 4.7us 0.6us setup time for a repeated start condition
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// Tsu:sto 4.0us 0.6us setup time for a stop conditon
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// Tbuf 4.7us 1.3us Bus free time between a stop and start condition
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//
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`include "i2c_master_defines.v"
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module i2c_master_bit_ctrl (
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input clk, // system clock
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input nReset, // asynchronous active low reset
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input ena, // core enable signal
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input [15:0] clk_cnt, // clock prescale value
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input [ 3:0] cmd, // command (from byte controller)
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output reg cmd_ack, // command complete acknowledge
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output reg busy, // i2c bus busy
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output reg al, // i2c bus arbitration lost
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input din,
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output reg dout,
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input scl_i, // i2c clock line input
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output scl_o, // i2c clock line output
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output reg scl_oen, // i2c clock line output enable (active low)
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input sda_i, // i2c data line input
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output sda_o, // i2c data line output
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output reg sda_oen // i2c data line output enable (active low)
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);
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//
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// variable declarations
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//
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reg [ 1:0] cSCL, cSDA; // capture SCL and SDA
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reg [ 2:0] fSCL, fSDA; // SCL and SDA filter inputs
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reg sSCL, sSDA; // filtered and synchronized SCL and SDA inputs
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reg dSCL, dSDA; // delayed versions of sSCL and sSDA
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reg dscl_oen; // delayed scl_oen
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reg sda_chk; // check SDA output (Multi-master arbitration)
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reg clk_en; // clock generation signals
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reg slave_wait; // slave inserts wait states
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reg [15:0] cnt; // clock divider counter (synthesis)
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reg [13:0] filter_cnt; // clock divider for filter
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// state machine variable
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reg [17:0] c_state;
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//
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// module body
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//
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// whenever the slave is not ready it can delay the cycle by pulling SCL low
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// delay scl_oen
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always @(posedge clk)
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dscl_oen <= scl_oen;
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// slave_wait is asserted when master wants to drive SCL high, but the slave pulls it low
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// slave_wait remains asserted until the slave releases SCL
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always @(posedge clk or negedge nReset)
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if (!nReset) slave_wait <= 1'b0;
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else slave_wait <= (scl_oen & ~dscl_oen & ~sSCL) | (slave_wait & ~sSCL);
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// master drives SCL high, but another master pulls it low
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// master start counting down its low cycle now (clock synchronization)
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wire scl_sync = dSCL & ~sSCL & scl_oen;
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// generate clk enable signal
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always @(posedge clk or negedge nReset)
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if (~nReset)
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begin
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cnt <= 16'h0;
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clk_en <= 1'b1;
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end
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else if (~|cnt || !ena || scl_sync)
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begin
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cnt <= clk_cnt;
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clk_en <= 1'b1;
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end
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else if (slave_wait)
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begin
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cnt <= cnt;
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clk_en <= 1'b0;
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end
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else
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begin
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cnt <= cnt - 16'h1;
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clk_en <= 1'b0;
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end
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// generate bus status controller
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// capture SDA and SCL
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// reduce metastability risk
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always @(posedge clk or negedge nReset)
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if (!nReset)
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begin
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cSCL <= 2'b00;
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cSDA <= 2'b00;
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end
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else
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begin
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cSCL <= {cSCL[0],scl_i};
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cSDA <= {cSDA[0],sda_i};
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end
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// filter SCL and SDA signals; (attempt to) remove glitches
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always @(posedge clk or negedge nReset)
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if (!nReset ) filter_cnt <= 14'h0;
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else if (!ena ) filter_cnt <= 14'h0;
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else if (~|filter_cnt) filter_cnt <= clk_cnt >> 2; //16x I2C bus frequency
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else filter_cnt <= filter_cnt -1;
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always @(posedge clk or negedge nReset)
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if (!nReset)
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begin
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fSCL <= 3'b111;
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fSDA <= 3'b111;
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end
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else if (~|filter_cnt)
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begin
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fSCL <= {fSCL[1:0],cSCL[1]};
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fSDA <= {fSDA[1:0],cSDA[1]};
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end
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// generate filtered SCL and SDA signals
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always @(posedge clk or negedge nReset)
|
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if (~nReset)
|
||||
begin
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sSCL <= 1'b1;
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sSDA <= 1'b1;
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dSCL <= 1'b1;
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dSDA <= 1'b1;
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||||
end
|
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else
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begin
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sSCL <= &fSCL[2:1] | &fSCL[1:0] | (fSCL[2] & fSCL[0]);
|
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sSDA <= &fSDA[2:1] | &fSDA[1:0] | (fSDA[2] & fSDA[0]);
|
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|
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dSCL <= sSCL;
|
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dSDA <= sSDA;
|
||||
end
|
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|
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// detect start condition => detect falling edge on SDA while SCL is high
|
||||
// detect stop condition => detect rising edge on SDA while SCL is high
|
||||
reg sta_condition;
|
||||
reg sto_condition;
|
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always @(posedge clk or negedge nReset)
|
||||
if (~nReset)
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||||
begin
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sta_condition <= 1'b0;
|
||||
sto_condition <= 1'b0;
|
||||
end
|
||||
else
|
||||
begin
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||||
sta_condition <= ~sSDA & dSDA & sSCL;
|
||||
sto_condition <= sSDA & ~dSDA & sSCL;
|
||||
end
|
||||
|
||||
|
||||
// generate i2c bus busy signal
|
||||
always @(posedge clk or negedge nReset)
|
||||
if (!nReset) busy <= 1'b0;
|
||||
else busy <= (sta_condition | busy) & ~sto_condition;
|
||||
|
||||
|
||||
// generate arbitration lost signal
|
||||
// aribitration lost when:
|
||||
// 1) master drives SDA high, but the i2c bus is low
|
||||
// 2) stop detected while not requested
|
||||
reg cmd_stop;
|
||||
always @(posedge clk or negedge nReset)
|
||||
if (~nReset)
|
||||
cmd_stop <= 1'b0;
|
||||
else if (clk_en)
|
||||
cmd_stop <= cmd == `I2C_CMD_STOP;
|
||||
|
||||
always @(posedge clk or negedge nReset)
|
||||
if (~nReset)
|
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al <= 1'b0;
|
||||
else
|
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al <= (sda_chk & ~sSDA & sda_oen) | (|c_state & sto_condition & ~cmd_stop);
|
||||
|
||||
|
||||
// generate dout signal (store SDA on rising edge of SCL)
|
||||
always @(posedge clk)
|
||||
if (sSCL & ~dSCL) dout <= sSDA;
|
||||
|
||||
|
||||
// generate statemachine
|
||||
|
||||
// nxt_state decoder
|
||||
parameter [17:0] idle = 18'b0_0000_0000_0000_0000;
|
||||
parameter [17:0] start_a = 18'b0_0000_0000_0000_0001;
|
||||
parameter [17:0] start_b = 18'b0_0000_0000_0000_0010;
|
||||
parameter [17:0] start_c = 18'b0_0000_0000_0000_0100;
|
||||
parameter [17:0] start_d = 18'b0_0000_0000_0000_1000;
|
||||
parameter [17:0] start_e = 18'b0_0000_0000_0001_0000;
|
||||
parameter [17:0] stop_a = 18'b0_0000_0000_0010_0000;
|
||||
parameter [17:0] stop_b = 18'b0_0000_0000_0100_0000;
|
||||
parameter [17:0] stop_c = 18'b0_0000_0000_1000_0000;
|
||||
parameter [17:0] stop_d = 18'b0_0000_0001_0000_0000;
|
||||
parameter [17:0] rd_a = 18'b0_0000_0010_0000_0000;
|
||||
parameter [17:0] rd_b = 18'b0_0000_0100_0000_0000;
|
||||
parameter [17:0] rd_c = 18'b0_0000_1000_0000_0000;
|
||||
parameter [17:0] rd_d = 18'b0_0001_0000_0000_0000;
|
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parameter [17:0] wr_a = 18'b0_0010_0000_0000_0000;
|
||||
parameter [17:0] wr_b = 18'b0_0100_0000_0000_0000;
|
||||
parameter [17:0] wr_c = 18'b0_1000_0000_0000_0000;
|
||||
parameter [17:0] wr_d = 18'b1_0000_0000_0000_0000;
|
||||
|
||||
always @(posedge clk or negedge nReset)
|
||||
if (!nReset)
|
||||
begin
|
||||
c_state <= idle;
|
||||
cmd_ack <= 1'b0;
|
||||
scl_oen <= 1'b1;
|
||||
sda_oen <= 1'b1;
|
||||
sda_chk <= 1'b0;
|
||||
end
|
||||
else if (al)
|
||||
begin
|
||||
c_state <= idle;
|
||||
cmd_ack <= 1'b0;
|
||||
scl_oen <= 1'b1;
|
||||
sda_oen <= 1'b1;
|
||||
sda_chk <= 1'b0;
|
||||
end
|
||||
else
|
||||
begin
|
||||
cmd_ack <= 1'b0; // default no command acknowledge + assert cmd_ack only 1clk cycle
|
||||
|
||||
if (clk_en)
|
||||
case (c_state)
|
||||
// idle state
|
||||
idle:
|
||||
begin
|
||||
case (cmd)
|
||||
`I2C_CMD_START: c_state <= start_a;
|
||||
`I2C_CMD_STOP: c_state <= stop_a;
|
||||
`I2C_CMD_WRITE: c_state <= wr_a;
|
||||
`I2C_CMD_READ: c_state <= rd_a;
|
||||
default: c_state <= idle;
|
||||
endcase
|
||||
|
||||
scl_oen <= scl_oen; // keep SCL in same state
|
||||
sda_oen <= sda_oen; // keep SDA in same state
|
||||
sda_chk <= 1'b0; // don't check SDA output
|
||||
end
|
||||
|
||||
// start
|
||||
start_a:
|
||||
begin
|
||||
c_state <= start_b;
|
||||
scl_oen <= scl_oen; // keep SCL in same state
|
||||
sda_oen <= 1'b1; // set SDA high
|
||||
sda_chk <= 1'b0; // don't check SDA output
|
||||
end
|
||||
|
||||
start_b:
|
||||
begin
|
||||
c_state <= start_c;
|
||||
scl_oen <= 1'b1; // set SCL high
|
||||
sda_oen <= 1'b1; // keep SDA high
|
||||
sda_chk <= 1'b0; // don't check SDA output
|
||||
end
|
||||
|
||||
start_c:
|
||||
begin
|
||||
c_state <= start_d;
|
||||
scl_oen <= 1'b1; // keep SCL high
|
||||
sda_oen <= 1'b0; // set SDA low
|
||||
sda_chk <= 1'b0; // don't check SDA output
|
||||
end
|
||||
|
||||
start_d:
|
||||
begin
|
||||
c_state <= start_e;
|
||||
scl_oen <= 1'b1; // keep SCL high
|
||||
sda_oen <= 1'b0; // keep SDA low
|
||||
sda_chk <= 1'b0; // don't check SDA output
|
||||
end
|
||||
|
||||
start_e:
|
||||
begin
|
||||
c_state <= idle;
|
||||
cmd_ack <= 1'b1;
|
||||
scl_oen <= 1'b0; // set SCL low
|
||||
sda_oen <= 1'b0; // keep SDA low
|
||||
sda_chk <= 1'b0; // don't check SDA output
|
||||
end
|
||||
|
||||
// stop
|
||||
stop_a:
|
||||
begin
|
||||
c_state <= stop_b;
|
||||
scl_oen <= 1'b0; // keep SCL low
|
||||
sda_oen <= 1'b0; // set SDA low
|
||||
sda_chk <= 1'b0; // don't check SDA output
|
||||
end
|
||||
|
||||
stop_b:
|
||||
begin
|
||||
c_state <= stop_c;
|
||||
scl_oen <= 1'b1; // set SCL high
|
||||
sda_oen <= 1'b0; // keep SDA low
|
||||
sda_chk <= 1'b0; // don't check SDA output
|
||||
end
|
||||
|
||||
stop_c:
|
||||
begin
|
||||
c_state <= stop_d;
|
||||
scl_oen <= 1'b1; // keep SCL high
|
||||
sda_oen <= 1'b0; // keep SDA low
|
||||
sda_chk <= 1'b0; // don't check SDA output
|
||||
end
|
||||
|
||||
stop_d:
|
||||
begin
|
||||
c_state <= idle;
|
||||
cmd_ack <= 1'b1;
|
||||
scl_oen <= 1'b1; // keep SCL high
|
||||
sda_oen <= 1'b1; // set SDA high
|
||||
sda_chk <= 1'b0; // don't check SDA output
|
||||
end
|
||||
|
||||
// read
|
||||
rd_a:
|
||||
begin
|
||||
c_state <= rd_b;
|
||||
scl_oen <= 1'b0; // keep SCL low
|
||||
sda_oen <= 1'b1; // tri-state SDA
|
||||
sda_chk <= 1'b0; // don't check SDA output
|
||||
end
|
||||
|
||||
rd_b:
|
||||
begin
|
||||
c_state <= rd_c;
|
||||
scl_oen <= 1'b1; // set SCL high
|
||||
sda_oen <= 1'b1; // keep SDA tri-stated
|
||||
sda_chk <= 1'b0; // don't check SDA output
|
||||
end
|
||||
|
||||
rd_c:
|
||||
begin
|
||||
c_state <= rd_d;
|
||||
scl_oen <= 1'b1; // keep SCL high
|
||||
sda_oen <= 1'b1; // keep SDA tri-stated
|
||||
sda_chk <= 1'b0; // don't check SDA output
|
||||
end
|
||||
|
||||
rd_d:
|
||||
begin
|
||||
c_state <= idle;
|
||||
cmd_ack <= 1'b1;
|
||||
scl_oen <= 1'b0; // set SCL low
|
||||
sda_oen <= 1'b1; // keep SDA tri-stated
|
||||
sda_chk <= 1'b0; // don't check SDA output
|
||||
end
|
||||
|
||||
// write
|
||||
wr_a:
|
||||
begin
|
||||
c_state <= wr_b;
|
||||
scl_oen <= 1'b0; // keep SCL low
|
||||
sda_oen <= din; // set SDA
|
||||
sda_chk <= 1'b0; // don't check SDA output (SCL low)
|
||||
end
|
||||
|
||||
wr_b:
|
||||
begin
|
||||
c_state <= wr_c;
|
||||
scl_oen <= 1'b1; // set SCL high
|
||||
sda_oen <= din; // keep SDA
|
||||
sda_chk <= 1'b0; // don't check SDA output yet
|
||||
// allow some time for SDA and SCL to settle
|
||||
end
|
||||
|
||||
wr_c:
|
||||
begin
|
||||
c_state <= wr_d;
|
||||
scl_oen <= 1'b1; // keep SCL high
|
||||
sda_oen <= din;
|
||||
sda_chk <= 1'b1; // check SDA output
|
||||
end
|
||||
|
||||
wr_d:
|
||||
begin
|
||||
c_state <= idle;
|
||||
cmd_ack <= 1'b1;
|
||||
scl_oen <= 1'b0; // set SCL low
|
||||
sda_oen <= din;
|
||||
sda_chk <= 1'b0; // don't check SDA output (SCL low)
|
||||
end
|
||||
|
||||
endcase
|
||||
end
|
||||
|
||||
|
||||
// assign scl and sda output (always gnd)
|
||||
assign scl_o = 1'b0;
|
||||
assign sda_o = 1'b0;
|
||||
|
||||
endmodule
|
||||
@@ -0,0 +1,334 @@
|
||||
/////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// WISHBONE rev.B2 compliant I2C Master byte-controller ////
|
||||
//// ////
|
||||
//// ////
|
||||
//// Author: Richard Herveille ////
|
||||
//// richard@asics.ws ////
|
||||
//// www.asics.ws ////
|
||||
//// ////
|
||||
//// Downloaded from: http://www.opencores.org/projects/i2c/ ////
|
||||
//// ////
|
||||
/////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// Copyright (C) 2001 Richard Herveille ////
|
||||
//// richard@asics.ws ////
|
||||
//// ////
|
||||
//// This source file may be used and distributed without ////
|
||||
//// restriction provided that this copyright statement is not ////
|
||||
//// removed from the file and that any derivative work contains ////
|
||||
//// the original copyright notice and the associated disclaimer.////
|
||||
//// ////
|
||||
//// THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY ////
|
||||
//// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED ////
|
||||
//// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS ////
|
||||
//// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR ////
|
||||
//// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, ////
|
||||
//// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES ////
|
||||
//// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE ////
|
||||
//// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR ////
|
||||
//// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF ////
|
||||
//// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ////
|
||||
//// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT ////
|
||||
//// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE ////
|
||||
//// POSSIBILITY OF SUCH DAMAGE. ////
|
||||
//// ////
|
||||
/////////////////////////////////////////////////////////////////////
|
||||
|
||||
// CVS Log
|
||||
//
|
||||
// $Id: i2c_master_byte_ctrl.v,v 1.8 2009-01-19 20:29:26 rherveille Exp $
|
||||
//
|
||||
// $Date: 2009-01-19 20:29:26 $
|
||||
// $Revision: 1.8 $
|
||||
// $Author: rherveille $
|
||||
// $Locker: $
|
||||
// $State: Exp $
|
||||
//
|
||||
// Change History:
|
||||
// $Log: not supported by cvs2svn $
|
||||
// Revision 1.7 2004/02/18 11:40:46 rherveille
|
||||
// Fixed a potential bug in the statemachine. During a 'stop' 2 cmd_ack signals were generated. Possibly canceling a new start command.
|
||||
//
|
||||
// Revision 1.6 2003/08/09 07:01:33 rherveille
|
||||
// Fixed a bug in the Arbitration Lost generation caused by delay on the (external) sda line.
|
||||
// Fixed a potential bug in the byte controller's host-acknowledge generation.
|
||||
//
|
||||
// Revision 1.5 2002/12/26 15:02:32 rherveille
|
||||
// Core is now a Multimaster I2C controller
|
||||
//
|
||||
// Revision 1.4 2002/11/30 22:24:40 rherveille
|
||||
// Cleaned up code
|
||||
//
|
||||
// Revision 1.3 2001/11/05 11:59:25 rherveille
|
||||
// Fixed wb_ack_o generation bug.
|
||||
// Fixed bug in the byte_controller statemachine.
|
||||
// Added headers.
|
||||
//
|
||||
|
||||
`include "i2c_master_defines.v"
|
||||
|
||||
module i2c_master_byte_ctrl (
|
||||
clk, nReset, ena, clk_cnt, start, stop, read, write, ack_in, din,
|
||||
cmd_ack, ack_out, dout, i2c_busy, i2c_al, scl_i, scl_o, scl_oen, sda_i, sda_o, sda_oen );
|
||||
|
||||
//
|
||||
// inputs & outputs
|
||||
//
|
||||
input clk; // master clock
|
||||
input nReset; // synchronous active low reset
|
||||
input ena; // core enable signal
|
||||
|
||||
input [15:0] clk_cnt; // 4x SCL
|
||||
|
||||
// control inputs
|
||||
input start;
|
||||
input stop;
|
||||
input read;
|
||||
input write;
|
||||
input ack_in;
|
||||
input [7:0] din;
|
||||
|
||||
// status outputs
|
||||
output cmd_ack;
|
||||
reg cmd_ack;
|
||||
output ack_out;
|
||||
reg ack_out;
|
||||
output i2c_busy;
|
||||
output i2c_al;
|
||||
output [7:0] dout;
|
||||
|
||||
// I2C signals
|
||||
input scl_i;
|
||||
output scl_o;
|
||||
output scl_oen;
|
||||
input sda_i;
|
||||
output sda_o;
|
||||
output sda_oen;
|
||||
|
||||
|
||||
//
|
||||
// Variable declarations
|
||||
//
|
||||
|
||||
// statemachine
|
||||
parameter [4:0] ST_IDLE = 5'b0_0000;
|
||||
parameter [4:0] ST_START = 5'b0_0001;
|
||||
parameter [4:0] ST_READ = 5'b0_0010;
|
||||
parameter [4:0] ST_WRITE = 5'b0_0100;
|
||||
parameter [4:0] ST_ACK = 5'b0_1000;
|
||||
parameter [4:0] ST_STOP = 5'b1_0000;
|
||||
|
||||
// signals for bit_controller
|
||||
reg [3:0] core_cmd;
|
||||
reg core_txd;
|
||||
wire core_ack, core_rxd;
|
||||
|
||||
// signals for shift register
|
||||
reg [7:0] sr; //8bit shift register
|
||||
reg shift, ld;
|
||||
|
||||
// signals for state machine
|
||||
wire go;
|
||||
reg [2:0] dcnt;
|
||||
wire cnt_done;
|
||||
|
||||
//
|
||||
// Module body
|
||||
//
|
||||
|
||||
// hookup bit_controller
|
||||
i2c_master_bit_ctrl bit_controller (
|
||||
.clk ( clk ),
|
||||
.nReset ( nReset ),
|
||||
.ena ( ena ),
|
||||
.clk_cnt ( clk_cnt ),
|
||||
.cmd ( core_cmd ),
|
||||
.cmd_ack ( core_ack ),
|
||||
.busy ( i2c_busy ),
|
||||
.al ( i2c_al ),
|
||||
.din ( core_txd ),
|
||||
.dout ( core_rxd ),
|
||||
.scl_i ( scl_i ),
|
||||
.scl_o ( scl_o ),
|
||||
.scl_oen ( scl_oen ),
|
||||
.sda_i ( sda_i ),
|
||||
.sda_o ( sda_o ),
|
||||
.sda_oen ( sda_oen )
|
||||
);
|
||||
|
||||
// generate go-signal
|
||||
assign go = (read | write | stop) & ~cmd_ack;
|
||||
|
||||
// assign dout output to shift-register
|
||||
assign dout = sr;
|
||||
|
||||
// generate shift register
|
||||
always @(posedge clk or negedge nReset)
|
||||
if (!nReset)
|
||||
sr <= 8'h0;
|
||||
else if (ld)
|
||||
sr <= din;
|
||||
else if (shift)
|
||||
sr <= {sr[6:0], core_rxd};
|
||||
|
||||
// generate counter
|
||||
always @(posedge clk or negedge nReset)
|
||||
if (!nReset)
|
||||
dcnt <= 3'h0;
|
||||
else if (ld)
|
||||
dcnt <= 3'h7;
|
||||
else if (shift)
|
||||
dcnt <= dcnt - 3'h1;
|
||||
|
||||
assign cnt_done = ~(|dcnt);
|
||||
|
||||
//
|
||||
// state machine
|
||||
//
|
||||
reg [4:0] c_state;
|
||||
|
||||
always @(posedge clk or negedge nReset)
|
||||
if (!nReset)
|
||||
begin
|
||||
core_cmd <= `I2C_CMD_NOP;
|
||||
core_txd <= 1'b0;
|
||||
shift <= 1'b0;
|
||||
ld <= 1'b0;
|
||||
cmd_ack <= 1'b0;
|
||||
c_state <= ST_IDLE;
|
||||
ack_out <= 1'b0;
|
||||
end
|
||||
else if (i2c_al)
|
||||
begin
|
||||
core_cmd <= `I2C_CMD_NOP;
|
||||
core_txd <= 1'b0;
|
||||
shift <= 1'b0;
|
||||
ld <= 1'b0;
|
||||
cmd_ack <= 1'b0;
|
||||
c_state <= ST_IDLE;
|
||||
ack_out <= 1'b0;
|
||||
end
|
||||
else
|
||||
begin
|
||||
// initially reset all signals
|
||||
core_txd <= sr[7];
|
||||
shift <= 1'b0;
|
||||
ld <= 1'b0;
|
||||
cmd_ack <= 1'b0;
|
||||
|
||||
case (c_state)
|
||||
ST_IDLE:
|
||||
if (go)
|
||||
begin
|
||||
if (start)
|
||||
begin
|
||||
c_state <= ST_START;
|
||||
core_cmd <= `I2C_CMD_START;
|
||||
end
|
||||
else if (read)
|
||||
begin
|
||||
c_state <= ST_READ;
|
||||
core_cmd <= `I2C_CMD_READ;
|
||||
end
|
||||
else if (write)
|
||||
begin
|
||||
c_state <= ST_WRITE;
|
||||
core_cmd <= `I2C_CMD_WRITE;
|
||||
end
|
||||
else // stop
|
||||
begin
|
||||
c_state <= ST_STOP;
|
||||
core_cmd <= `I2C_CMD_STOP;
|
||||
end
|
||||
|
||||
ld <= 1'b1;
|
||||
end
|
||||
|
||||
ST_START:
|
||||
if (core_ack)
|
||||
begin
|
||||
if (read)
|
||||
begin
|
||||
c_state <= ST_READ;
|
||||
core_cmd <= `I2C_CMD_READ;
|
||||
end
|
||||
else
|
||||
begin
|
||||
c_state <= ST_WRITE;
|
||||
core_cmd <= `I2C_CMD_WRITE;
|
||||
end
|
||||
|
||||
ld <= 1'b1;
|
||||
end
|
||||
|
||||
ST_WRITE:
|
||||
if (core_ack)
|
||||
if (cnt_done)
|
||||
begin
|
||||
c_state <= ST_ACK;
|
||||
core_cmd <= `I2C_CMD_READ;
|
||||
end
|
||||
else
|
||||
begin
|
||||
c_state <= ST_WRITE; // stay in same state
|
||||
core_cmd <= `I2C_CMD_WRITE; // write next bit
|
||||
shift <= 1'b1;
|
||||
end
|
||||
|
||||
ST_READ:
|
||||
if (core_ack)
|
||||
begin
|
||||
if (cnt_done)
|
||||
begin
|
||||
c_state <= ST_ACK;
|
||||
core_cmd <= `I2C_CMD_WRITE;
|
||||
end
|
||||
else
|
||||
begin
|
||||
c_state <= ST_READ; // stay in same state
|
||||
core_cmd <= `I2C_CMD_READ; // read next bit
|
||||
end
|
||||
|
||||
shift <= 1'b1;
|
||||
core_txd <= ack_in;
|
||||
end
|
||||
|
||||
ST_ACK:
|
||||
if (core_ack)
|
||||
begin
|
||||
if (stop)
|
||||
begin
|
||||
c_state <= ST_STOP;
|
||||
core_cmd <= `I2C_CMD_STOP;
|
||||
end
|
||||
else
|
||||
begin
|
||||
c_state <= ST_IDLE;
|
||||
core_cmd <= `I2C_CMD_NOP;
|
||||
|
||||
// generate command acknowledge signal
|
||||
cmd_ack <= 1'b1;
|
||||
end
|
||||
|
||||
// assign ack_out output to bit_controller_rxd (contains last received bit)
|
||||
ack_out <= core_rxd;
|
||||
|
||||
core_txd <= 1'b1;
|
||||
end
|
||||
else
|
||||
core_txd <= ack_in;
|
||||
|
||||
ST_STOP:
|
||||
if (core_ack)
|
||||
begin
|
||||
c_state <= ST_IDLE;
|
||||
core_cmd <= `I2C_CMD_NOP;
|
||||
|
||||
// generate command acknowledge signal
|
||||
cmd_ack <= 1'b1;
|
||||
end
|
||||
|
||||
endcase
|
||||
end
|
||||
endmodule
|
||||
@@ -0,0 +1,59 @@
|
||||
/////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// WISHBONE rev.B2 compliant I2C Master controller defines ////
|
||||
//// ////
|
||||
//// ////
|
||||
//// Author: Richard Herveille ////
|
||||
//// richard@asics.ws ////
|
||||
//// www.asics.ws ////
|
||||
//// ////
|
||||
//// Downloaded from: http://www.opencores.org/projects/i2c/ ////
|
||||
//// ////
|
||||
/////////////////////////////////////////////////////////////////////
|
||||
//// ////
|
||||
//// Copyright (C) 2001 Richard Herveille ////
|
||||
//// richard@asics.ws ////
|
||||
//// ////
|
||||
//// This source file may be used and distributed without ////
|
||||
//// restriction provided that this copyright statement is not ////
|
||||
//// removed from the file and that any derivative work contains ////
|
||||
//// the original copyright notice and the associated disclaimer.////
|
||||
//// ////
|
||||
//// THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY ////
|
||||
//// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED ////
|
||||
//// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS ////
|
||||
//// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR ////
|
||||
//// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, ////
|
||||
//// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES ////
|
||||
//// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE ////
|
||||
//// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR ////
|
||||
//// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF ////
|
||||
//// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ////
|
||||
//// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT ////
|
||||
//// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE ////
|
||||
//// POSSIBILITY OF SUCH DAMAGE. ////
|
||||
//// ////
|
||||
/////////////////////////////////////////////////////////////////////
|
||||
|
||||
// CVS Log
|
||||
//
|
||||
// $Id: i2c_master_defines.v,v 1.3 2001-11-05 11:59:25 rherveille Exp $
|
||||
//
|
||||
// $Date: 2001-11-05 11:59:25 $
|
||||
// $Revision: 1.3 $
|
||||
// $Author: rherveille $
|
||||
// $Locker: $
|
||||
// $State: Exp $
|
||||
//
|
||||
// Change History:
|
||||
// $Log: not supported by cvs2svn $
|
||||
|
||||
|
||||
// I2C registers wishbone addresses
|
||||
|
||||
// bitcontroller states
|
||||
`define I2C_CMD_NOP 4'b0000
|
||||
`define I2C_CMD_START 4'b0001
|
||||
`define I2C_CMD_STOP 4'b0010
|
||||
`define I2C_CMD_WRITE 4'b0100
|
||||
`define I2C_CMD_READ 4'b1000
|
||||
@@ -0,0 +1,72 @@
|
||||
/*******************************************************************
|
||||
*
|
||||
* Module: i2c_slave.v
|
||||
* Project: Ravenna
|
||||
* Author: mshalan (modified by Tim Edwards)
|
||||
* Description: An i2c slave for i2c master testbench
|
||||
*
|
||||
**********************************************************************/
|
||||
|
||||
module i2c_slave(
|
||||
inout scl, sda
|
||||
);
|
||||
|
||||
parameter[7:0] SIDLE=8'h1, SADDR=8'h2, SACK1=8'h4, SDATA=8'h8, SACK2=8'h10;
|
||||
|
||||
reg scl_en, sda_en;
|
||||
|
||||
reg sda_o, scl_o;
|
||||
wire sda_i, scl_i;
|
||||
|
||||
assign sda = sda_en ? sda_o : 1'bz;
|
||||
assign scl = scl_en ? scl_o : 1'bz;
|
||||
|
||||
assign scl_i = scl;
|
||||
assign sda_i = sda;
|
||||
|
||||
reg[4:0] cntr;
|
||||
reg[7:0] state, addr, data;
|
||||
reg[1:0] cfsm;
|
||||
|
||||
// Start Bit
|
||||
always @ (negedge sda_i)
|
||||
if(scl_i) begin
|
||||
state <= SADDR;
|
||||
addr <= 8'd0;
|
||||
data <= 0;
|
||||
cntr <= 0;
|
||||
end
|
||||
|
||||
always @ (posedge scl_i)
|
||||
if(state == SADDR) begin
|
||||
addr <= {addr[6:0], sda_i};
|
||||
end
|
||||
else
|
||||
if(state == SDATA) begin
|
||||
data <= {data[6:0], sda_i};
|
||||
end
|
||||
|
||||
always @ (posedge scl_i)
|
||||
if((state== SADDR) || (state==SDATA)) cntr <= cntr + 1;
|
||||
|
||||
always @ (negedge scl_i)
|
||||
if(cntr==8 )
|
||||
sda_en <= 1;
|
||||
else
|
||||
sda_en <= 0;
|
||||
|
||||
always @ (negedge scl_i)
|
||||
if(cntr==8) state = SDATA;
|
||||
else if((state== SDATA) && (cntr==17)) begin
|
||||
state<=SIDLE;
|
||||
$display("i2c Slave has received 0x%X - Address: 0x%X", data, addr);
|
||||
end
|
||||
|
||||
initial begin
|
||||
scl_en = 0;
|
||||
sda_en = 0;
|
||||
sda_o = 0;
|
||||
state <= SIDLE;
|
||||
end
|
||||
|
||||
endmodule
|
||||
@@ -0,0 +1,312 @@
|
||||
//----------------------------------------------------------------------------
|
||||
// Module: simple_spi_master
|
||||
//
|
||||
//----------------------------------------------------------------------------
|
||||
// Copyright (C) 2019 efabless, inc.
|
||||
//
|
||||
// This source file may be used and distributed without
|
||||
// restriction provided that this copyright statement is not
|
||||
// removed from the file and that any derivative work contains
|
||||
// the original copyright notice and the associated disclaimer.
|
||||
//
|
||||
// This source file is free software; you can redistribute it
|
||||
// and/or modify it under the terms of the GNU Lesser General
|
||||
// Public License as published by the Free Software Foundation;
|
||||
// either version 2.1 of the License, or (at your option) any
|
||||
// later version.
|
||||
//
|
||||
// This source is distributed in the hope that it will be
|
||||
// useful, but WITHOUT ANY WARRANTY; without even the implied
|
||||
// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
|
||||
// PURPOSE. See the GNU Lesser General Public License for more
|
||||
// details.
|
||||
//
|
||||
//--------------------------------------------------------------------
|
||||
//
|
||||
// resetn: active low async reset
|
||||
// clk: master clock (before prescaler)
|
||||
// stream:
|
||||
// 0 = apply/release CSB separately for each byte
|
||||
// 1 = apply CSB until stream bit is cleared
|
||||
// mlb:
|
||||
// 0 = msb 1st
|
||||
// 1 = lsb 1st
|
||||
// invsck:
|
||||
// 0 = normal SCK
|
||||
// 1 = inverted SCK
|
||||
// invcsb:
|
||||
// 0 = normal CSB (active low)
|
||||
// 1 = inverted CSB (active high)
|
||||
// mode:
|
||||
// 0 = read and change data on opposite SCK edges
|
||||
// 1 = read and change data on the same SCK edge
|
||||
// enable:
|
||||
// 0 = disable the SPI master
|
||||
// 1 = enable the SPI master
|
||||
// irqena:
|
||||
// 0 = disable interrupt
|
||||
// 1 = enable interrupt
|
||||
// prescaler: count (in master clock cycles) of 1/2 SCK cycle.
|
||||
//
|
||||
// reg_dat_we:
|
||||
// 1 = data write enable
|
||||
// reg_dat_re:
|
||||
// 1 = data read enable
|
||||
// reg_cfg_*: Signaling for read/write of configuration register
|
||||
// reg_dat_*: Signaling for read/write of data register
|
||||
//
|
||||
// err_out: Indicates attempt to read/write before data ready
|
||||
// (failure to wait for reg_dat_wait to clear)
|
||||
//
|
||||
// Between "mode" and "invsck", all four standard SPI modes are supported
|
||||
//
|
||||
//--------------------------------------------------------------------
|
||||
|
||||
module simple_spi_master(
|
||||
input resetn,
|
||||
input clk, // master clock (assume 100MHz)
|
||||
|
||||
input [1:0] reg_cfg_we,
|
||||
input [31:0] reg_cfg_di,
|
||||
output [31:0] reg_cfg_do,
|
||||
|
||||
input reg_dat_we,
|
||||
input reg_dat_re,
|
||||
input [31:0] reg_dat_di,
|
||||
output [31:0] reg_dat_do,
|
||||
output reg_dat_wait,
|
||||
output irq_out,
|
||||
output reg err_out,
|
||||
|
||||
input sdi, // SPI input
|
||||
output csb, // SPI chip select
|
||||
output sck, // SPI clock
|
||||
output reg sdo, // SPI output
|
||||
output sdoenb // enable SDO output (active low)
|
||||
);
|
||||
|
||||
parameter IDLE = 2'b00;
|
||||
parameter SENDL = 2'b01;
|
||||
parameter SENDH = 2'b10;
|
||||
parameter FINISH = 2'b11;
|
||||
|
||||
reg done;
|
||||
reg hsck, icsb;
|
||||
// reg sdo;
|
||||
reg [1:0] state;
|
||||
reg isck;
|
||||
// reg err_out;
|
||||
|
||||
reg [7:0] treg, rreg, d_latched;
|
||||
reg [2:0] nbit;
|
||||
|
||||
reg [7:0] prescaler;
|
||||
reg [7:0] count;
|
||||
reg invsck;
|
||||
reg invcsb;
|
||||
reg mlb;
|
||||
reg irqena;
|
||||
reg stream;
|
||||
reg mode;
|
||||
reg enable;
|
||||
|
||||
// wire sdoenb;
|
||||
// wire csb;
|
||||
// wire irq_out;
|
||||
// wire sck;
|
||||
|
||||
// Define behavior for inverted SCK and inverted CSB
|
||||
assign csb = (invcsb) ? ~icsb : icsb;
|
||||
assign sck = (invsck) ? ~isck : isck;
|
||||
|
||||
// No bidirectional 3-pin mode defined, so SDO is enabled whenever CSB is low.
|
||||
assign sdoenb = icsb;
|
||||
|
||||
assign irq_out = irqena & done;
|
||||
|
||||
// Read configuration and data registers
|
||||
assign reg_cfg_do = {17'd0, irqena, enable, stream, mode, invsck, invcsb, mlb, prescaler};
|
||||
assign reg_dat_wait = ~done;
|
||||
assign reg_dat_do = done ? rreg : ~0;
|
||||
|
||||
// Write configuration register
|
||||
always @(posedge clk or negedge resetn) begin
|
||||
if (resetn == 1'b0) begin
|
||||
prescaler <= 8'd2;
|
||||
invcsb <= 1'b0;
|
||||
invsck <= 1'b0;
|
||||
mlb <= 1'b0;
|
||||
enable <= 1'b0;
|
||||
irqena <= 1'b0;
|
||||
stream <= 1'b0;
|
||||
mode <= 1'b0;
|
||||
end else begin
|
||||
if (reg_cfg_we[0]) prescaler <= reg_cfg_di[7:0];
|
||||
if (reg_cfg_we[1]) begin
|
||||
mlb <= reg_cfg_di[8];
|
||||
invcsb <= reg_cfg_di[9];
|
||||
invsck <= reg_cfg_di[10];
|
||||
mode <= reg_cfg_di[11];
|
||||
stream <= reg_cfg_di[12];
|
||||
enable <= reg_cfg_di[13];
|
||||
irqena <= reg_cfg_di[14];
|
||||
end //reg_cfg_we[1]
|
||||
end //resetn
|
||||
end //always
|
||||
|
||||
// Watch for read and write enables on clk, not hsck, so as not to
|
||||
// miss them.
|
||||
|
||||
reg w_latched, r_latched;
|
||||
|
||||
always @(posedge clk or negedge resetn) begin
|
||||
if (resetn == 1'b0) begin
|
||||
err_out <= 1'b0;
|
||||
w_latched <= 1'b0;
|
||||
r_latched <= 1'b0;
|
||||
d_latched <= 8'd0;
|
||||
end else begin
|
||||
// Clear latches on SEND, otherwise latch when seen
|
||||
if (state == SENDL || state == SENDH) begin
|
||||
if (reg_dat_we == 1'b0) begin
|
||||
w_latched <= 1'b0;
|
||||
end
|
||||
end else begin
|
||||
if (reg_dat_we == 1'b1) begin
|
||||
if (done == 1'b0 && w_latched == 1'b1) begin
|
||||
err_out <= 1'b1;
|
||||
end else begin
|
||||
w_latched <= 1'b1;
|
||||
d_latched <= reg_dat_di[7:0];
|
||||
err_out <= 1'b0;
|
||||
end
|
||||
end
|
||||
end
|
||||
|
||||
if (reg_dat_re == 1'b1) begin
|
||||
if (r_latched == 1'b1) begin
|
||||
r_latched <= 1'b0;
|
||||
end else begin
|
||||
err_out <= 1'b1; // byte not available
|
||||
end
|
||||
end else if (state == FINISH) begin
|
||||
r_latched <= 1'b1;
|
||||
end if (state == SENDL || state == SENDH) begin
|
||||
if (r_latched == 1'b1) begin
|
||||
err_out <= 1'b1; // last byte was never read
|
||||
end else begin
|
||||
r_latched <= 1'b0;
|
||||
end
|
||||
end
|
||||
end
|
||||
end
|
||||
|
||||
// State transition.
|
||||
|
||||
always @(posedge hsck or negedge resetn) begin
|
||||
if (resetn == 1'b0) begin
|
||||
state <= IDLE;
|
||||
nbit <= 3'd0;
|
||||
icsb <= 1'b1;
|
||||
done <= 1'b1;
|
||||
end else begin
|
||||
if (state == IDLE) begin
|
||||
if (w_latched == 1'b1) begin
|
||||
state <= SENDL;
|
||||
nbit <= 3'd0;
|
||||
icsb <= 1'b0;
|
||||
done <= 1'b0;
|
||||
end else begin
|
||||
icsb <= ~stream;
|
||||
end
|
||||
end else if (state == SENDL) begin
|
||||
state <= SENDH;
|
||||
end else if (state == SENDH) begin
|
||||
nbit <= nbit + 1;
|
||||
if (nbit == 3'd7) begin
|
||||
state <= FINISH;
|
||||
end else begin
|
||||
state <= SENDL;
|
||||
end
|
||||
end else if (state == FINISH) begin
|
||||
icsb <= ~stream;
|
||||
done <= 1'b1;
|
||||
state <= IDLE;
|
||||
end
|
||||
end
|
||||
end
|
||||
|
||||
// Set up internal clock. The enable bit gates the internal clock
|
||||
// to shut down the master SPI when disabled.
|
||||
|
||||
always @(posedge clk or negedge resetn) begin
|
||||
if (resetn == 1'b0) begin
|
||||
count <= 8'd0;
|
||||
hsck <= 1'b0;
|
||||
end else begin
|
||||
if (enable == 1'b0) begin
|
||||
count <= 8'd0;
|
||||
end else begin
|
||||
count <= count + 1;
|
||||
if (count == prescaler) begin
|
||||
hsck <= ~hsck;
|
||||
count <= 8'd0;
|
||||
end // count
|
||||
end // enable
|
||||
end // resetn
|
||||
end // always
|
||||
|
||||
// sck is half the rate of hsck
|
||||
|
||||
always @(posedge hsck or negedge resetn) begin
|
||||
if (resetn == 1'b0) begin
|
||||
isck <= 1'b0;
|
||||
end else begin
|
||||
if (state == IDLE || state == FINISH)
|
||||
isck <= 1'b0;
|
||||
else
|
||||
isck <= ~isck;
|
||||
end // resetn
|
||||
end // always
|
||||
|
||||
// Main procedure: read, write, shift data
|
||||
|
||||
always @(posedge hsck or negedge resetn) begin
|
||||
if (resetn == 1'b0) begin
|
||||
rreg <= 8'hff;
|
||||
treg <= 8'hff;
|
||||
sdo <= 1'b0;
|
||||
end else begin
|
||||
if (isck == 1'b0 && (state == SENDL || state == SENDH)) begin
|
||||
if (mlb == 1'b1) begin
|
||||
// LSB first, sdi@msb -> right shift
|
||||
rreg <= {sdi, rreg[7:1]};
|
||||
end else begin
|
||||
// MSB first, sdi@lsb -> left shift
|
||||
rreg <= {rreg[6:0], sdi};
|
||||
end
|
||||
end // read on ~isck
|
||||
|
||||
if (w_latched == 1'b1) begin
|
||||
if (mlb == 1'b1) begin
|
||||
treg <= {1'b1, d_latched[7:1]};
|
||||
sdo <= d_latched[0];
|
||||
end else begin
|
||||
treg <= {d_latched[6:0], 1'b1};
|
||||
sdo <= d_latched[7];
|
||||
end // mlb
|
||||
end else if ((mode ^ isck) == 1'b1) begin
|
||||
if (mlb == 1'b1) begin
|
||||
// LSB first, shift right
|
||||
treg <= {1'b1, treg[7:1]};
|
||||
sdo <= treg[0];
|
||||
end else begin
|
||||
// MSB first shift LEFT
|
||||
treg <= {treg[6:0], 1'b1};
|
||||
sdo <= treg[7];
|
||||
end // mlb
|
||||
end // write on mode ^ isck
|
||||
end // resetn
|
||||
end // always
|
||||
|
||||
endmodule
|
||||
Reference in new issue
Block a user