maksyuki
3b6a925a51
- Created documentation for , , , and modules, detailing their functionality, parameters, and usage examples. - Implemented a script to ensure required headings and content are present in documentation files. - Developed to generate and update documentation pages from SystemVerilog declarations, ensuring consistency and completeness.
3.2 KiB
stream_window_guard
| Property | Value |
|---|---|
| Kind | module |
| RTL source | rtl/stream/stream_control.sv |
| Availability | Synthesizable RTL |
Summary
Limits outstanding stream requests with explicit retire accounting.
Functional Behavior
Limits outstanding stream requests with explicit retire accounting. It follows the repository valid/ready rule: a payload transfers only when both signals are high in the same cycle, and a stalled valid payload remains stable.
Suitable Applications
Use for elastic pipelines, stream routing, arbitration, backpressure, and response handling.
Parameters
The declaration below is canonical; retain the RTL-enforced parameter range.
| Parameter | Declaration |
|---|---|
MAX_INFLIGHT |
parameter int MAX_INFLIGHT = 4 |
COUNT_WIDTH |
parameter int COUNT_WIDTH = $clog2(MAX_INFLIGHT + 1) |
Interface Definition
module stream_window_guard #(
parameter int MAX_INFLIGHT = 4,
parameter int COUNT_WIDTH = $clog2(MAX_INFLIGHT + 1)
) (
input logic clk_i,
input logic rst_n_i,
input logic flush_i,
input logic [COUNT_WIDTH-1:0] limit_i,
input logic submit_valid_i,
output logic submit_ready_o,
output logic forward_valid_o,
input logic forward_ready_i,
input logic retire_i,
output logic [COUNT_WIDTH-1:0] used_o
);
Port Summary
| Signal | Direction | Declaration |
|---|---|---|
clk_i |
input |
input logic clk_i |
rst_n_i |
input |
input logic rst_n_i |
flush_i |
input |
input logic flush_i |
limit_i |
input |
input logic [COUNT_WIDTH-1:0] limit_i |
submit_valid_i |
input |
input logic submit_valid_i |
submit_ready_o |
output |
output logic submit_ready_o |
forward_valid_o |
output |
output logic forward_valid_o |
forward_ready_i |
input |
input logic forward_ready_i |
retire_i |
input |
input logic retire_i |
used_o |
output |
output logic [COUNT_WIDTH-1:0] used_o |
Integration and Use
Observe vector sizing, selection encoding, and flush semantics in the declaration. Do not modify a valid payload while its corresponding ready is low.
stream_window_guard #(
.MAX_INFLIGHT(MAX_INFLIGHT),
.COUNT_WIDTH(COUNT_WIDTH)
) u_stream_window_guard (
.clk_i(clk_i),
.rst_n_i(rst_n_i),
.flush_i(flush_i),
.limit_i(limit_i),
.submit_valid_i(submit_valid_i),
.submit_ready_o(submit_ready_o),
.forward_valid_o(forward_valid_o),
.forward_ready_i(forward_ready_i),
.retire_i(retire_i),
.used_o(used_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.