Modified data mover to improve timing

main
Adrian Costina 2014-03-20 18:22:18 +02:00
parent 3a0d1282b7
commit 551319a670
1 changed files with 14 additions and 5 deletions

View File

@ -78,12 +78,15 @@ reg [C_ID_WIDTH-1:0] id_next = 'h00;
reg pending_burst = 1'b0;
reg active = 1'b0;
reg [C_ID_WIDTH-1:0] request_id_d1 = 'h0;
reg eot_d1 = 1'b0;
wire last;
wire last_load;
assign response_id = id;
assign last = beat_counter == (eot ? last_burst_length : MAX_BEATS_PER_BURST - 1);
assign last = beat_counter == (eot_d1 ? last_burst_length : MAX_BEATS_PER_BURST - 1);
assign s_axi_ready = m_axi_ready & pending_burst & active;
assign m_axi_valid = s_axi_valid & pending_burst & active;
@ -92,7 +95,7 @@ assign m_axi_last = last;
// If we want to support zero delay between transfers we have to assert
// req_ready on the same cycle on which the last load happens.
assign last_load = s_axi_ready && s_axi_valid && last && eot;
assign last_load = s_axi_ready && s_axi_valid && last && eot_d1;
assign req_ready = last_load || ~active;
always @(posedge clk) begin
@ -110,13 +113,18 @@ always @(posedge clk) begin
end else begin
// For memory mapped AXI busses we have to complete all pending
// burst requests before we can disable the data mover.
if (response_id == request_id)
if (response_id == request_id_d1)
enabled <= 1'b0;
end
end
end
end
always @(posedge clk) begin
eot_d1 <= eot;
request_id_d1 <= request_id;
end
always @(posedge clk) begin
if (resetn == 1'b0) begin
beat_counter <= 'h0;
@ -152,7 +160,7 @@ end
always @(*)
begin
if ((s_axi_ready && s_axi_valid && last) ||
(sync_id && pending_burst))
(sync_id && id != request_id))
id_next <= inc_id(id);
else
id_next <= id;
@ -164,7 +172,8 @@ always @(posedge clk) begin
pending_burst <= 1'b0;
end else begin
id <= id_next;
pending_burst <= id_next != request_id;
pending_burst <= id_next != request_id_d1;
end
end