common/docs/reference/utils/dffercn.md

dffercn

Property	Value
Kind	module
RTL source	rtl/utils/register.sv
Availability	Synthesizable RTL

Summary

Enabled D flip-flop with active-low configurable reset value.

Functional Behavior

Enabled D flip-flop with active-low configurable reset value. Its exact parameters and ports are reproduced below from the implementation declaration.

Suitable Applications

Use as a small reusable datapath, state, coding, delay, or verification primitive.

Parameters

The declaration below is canonical; retain the RTL-enforced parameter range.

Parameter	Declaration
REG_TYPE	parameter type REG_TYPE = logic
RESET_VAL	parameter REG_TYPE RESET_VAL = '0

Interface Definition

module dffercn #(
    parameter type     REG_TYPE  = logic,
    parameter REG_TYPE RESET_VAL = '0
) (
    input  logic    clk_i,
    input  logic    rst_n_i,
    input  logic    en_i,
    input  REG_TYPE dat_i,
    output REG_TYPE dat_o
);

Port Summary

Signal	Direction	Declaration
clk_i	input	input logic clk_i
rst_n_i	input	input logic rst_n_i
en_i	input	input logic en_i

Integration and Use

Keep parameter values within RTL assertions and add required clocking, reset, or CDC protection at the caller boundary.

dffercn #(
    .REG_TYPE(REG_TYPE),
    .RESET_VAL(RESET_VAL)
) u_dffercn (
    .clk_i(clk_i),
    .rst_n_i(rst_n_i),
    .en_i(en_i)
);

Dependencies and Verification

The linked RTL source is the implementation authority and contains local assertions for unsupported parameter combinations. See docs/design.md for repository-wide CDC, reset, stream, and storage contracts, and docs/verification.md for the verification matrix.