maksyuki
3b6a925a51
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2.8 KiB
address_map
| Property | Value |
|---|---|
| Kind | module |
| RTL source | rtl/bus/address_decode.sv |
| Availability | Synthesizable RTL |
Summary
Masked address-map decoder with deterministic lowest-index priority.
Functional Behavior
Masked address-map decoder with deterministic lowest-index priority. It classifies the presented address using the configured decode rule and returns the documented selection/match result combinationally.
Suitable Applications
Use for memory maps, peripheral selection, firewall regions, and target routing.
Parameters
The declaration below is canonical; retain the RTL-enforced parameter range.
| Parameter | Declaration |
|---|---|
ADDR_WIDTH |
parameter int ADDR_WIDTH = 32 |
REGIONS |
parameter int REGIONS = 4 |
INDEX_WIDTH |
parameter int INDEX_WIDTH = (REGIONS > 1) ? $clog2(REGIONS) : 1 |
Interface Definition
module address_map #(
parameter int ADDR_WIDTH = 32,
parameter int REGIONS = 4,
parameter int INDEX_WIDTH = (REGIONS > 1) ? $clog2(REGIONS) : 1
) (
input logic [ ADDR_WIDTH-1:0] addr_i,
input logic [ REGIONS-1:0][ADDR_WIDTH-1:0] base_i,
input logic [ REGIONS-1:0][ADDR_WIDTH-1:0] mask_i,
output logic [ REGIONS-1:0] hit_o,
output logic [INDEX_WIDTH-1:0] selected_o,
output logic valid_o
);
Port Summary
| Signal | Direction | Declaration |
|---|---|---|
addr_i |
input |
input logic [ ADDR_WIDTH-1:0] addr_i |
base_i |
input |
input logic [ REGIONS-1:0][ADDR_WIDTH-1:0] base_i |
mask_i |
input |
input logic [ REGIONS-1:0][ADDR_WIDTH-1:0] mask_i |
hit_o |
output |
output logic [ REGIONS-1:0] hit_o |
selected_o |
output |
output logic [INDEX_WIDTH-1:0] selected_o |
valid_o |
output |
output logic valid_o |
Integration and Use
Check overlaps and priority deliberately. Decode does not by itself complete or validate a bus transaction.
address_map #(
.ADDR_WIDTH(ADDR_WIDTH),
.REGIONS(REGIONS),
.INDEX_WIDTH(INDEX_WIDTH)
) u_address_map (
.addr_i(addr_i),
.base_i(base_i),
.mask_i(mask_i),
.hit_o(hit_o),
.selected_o(selected_o),
.valid_o(valid_o)
);
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.