refactoring all arbiters with buffering for request count > 2, optimized the cache core response module in critical path when running as L2

This commit is contained in:
Blaise Tine
2020-11-08 01:31:46 -08:00
parent b14007f930
commit 10505caae1
19 changed files with 602 additions and 534 deletions

View File

@@ -13,13 +13,13 @@ module VX_cache_dram_req_arb #(
// Inputs
input wire [NUM_BANKS-1:0] per_bank_dram_req_valid,
input wire [NUM_BANKS-1:0][`DRAM_ADDR_WIDTH-1:0] per_bank_dram_req_addr,
input wire [NUM_BANKS-1:0] per_bank_dram_req_rw,
input wire [NUM_BANKS-1:0][BANK_LINE_SIZE-1:0] per_bank_dram_req_byteen,
input wire [NUM_BANKS-1:0][`DRAM_ADDR_WIDTH-1:0] per_bank_dram_req_addr,
input wire [NUM_BANKS-1:0][`BANK_LINE_WIDTH-1:0] per_bank_dram_req_data,
output wire [NUM_BANKS-1:0] per_bank_dram_req_ready,
// Output
// Outputs
output wire dram_req_valid,
output wire dram_req_rw,
output wire [BANK_LINE_SIZE-1:0] dram_req_byteen,
@@ -28,36 +28,49 @@ module VX_cache_dram_req_arb #(
input wire dram_req_ready
);
wire sel_valid;
wire [`BANK_BITS-1:0] sel_idx;
wire [NUM_BANKS-1:0] sel_1hot;
VX_fixed_arbiter #(
.N(NUM_BANKS)
) sel_arb (
.clk (clk),
.reset (reset),
.requests (per_bank_dram_req_valid),
.grant_valid (sel_valid),
.grant_index (sel_idx),
.grant_onehot(sel_1hot)
);
if (NUM_BANKS > 1) begin
wire sel_valid;
wire [`BANK_BITS-1:0] sel_idx;
wire [NUM_BANKS-1:0] sel_1hot;
VX_rr_arbiter #(
.N(NUM_BANKS)
) sel_arb (
.clk (clk),
.reset (reset),
.requests (per_bank_dram_req_valid),
.grant_valid (sel_valid),
.grant_index (sel_idx),
.grant_onehot(sel_1hot)
);
wire stall = ~dram_req_ready && dram_req_valid;
wire stall = ~dram_req_ready && dram_req_valid;
VX_generic_register #(
.N(1 + 1 + BANK_LINE_SIZE + `DRAM_ADDR_WIDTH + `BANK_LINE_WIDTH)
) core_wb_reg (
.clk (clk),
.reset (reset),
.stall (stall),
.flush (1'b0),
.in ({sel_valid, per_bank_dram_req_rw[sel_idx], per_bank_dram_req_byteen[sel_idx], per_bank_dram_req_addr[sel_idx], per_bank_dram_req_data[sel_idx]}),
.out ({dram_req_valid, dram_req_rw, dram_req_byteen, dram_req_addr, dram_req_data})
);
VX_generic_register #(
.N(1 + `DRAM_ADDR_WIDTH + 1 + BANK_LINE_SIZE + `BANK_LINE_WIDTH),
.PASSTHRU(NUM_BANKS <= 2)
) pipe_reg (
.clk (clk),
.reset (reset),
.stall (stall),
.flush (1'b0),
.in ({sel_valid, per_bank_dram_req_addr[sel_idx], per_bank_dram_req_rw[sel_idx], per_bank_dram_req_byteen[sel_idx], per_bank_dram_req_data[sel_idx]}),
.out ({dram_req_valid, dram_req_addr, dram_req_rw, dram_req_byteen, dram_req_data})
);
for (genvar i = 0; i < NUM_BANKS; i++) begin
assign per_bank_dram_req_ready[i] = sel_1hot[i] && !stall;
for (genvar i = 0; i < NUM_BANKS; i++) begin
assign per_bank_dram_req_ready[i] = sel_1hot[i] && !stall;
end
end else begin
`UNUSED_VAR (clk)
`UNUSED_VAR (reset)
assign dram_req_valid = per_bank_dram_req_valid;
assign dram_req_rw = per_bank_dram_req_rw;
assign dram_req_byteen = per_bank_dram_req_byteen;
assign dram_req_addr = per_bank_dram_req_addr;
assign dram_req_data = per_bank_dram_req_data;
assign per_bank_dram_req_ready = dram_req_ready;
end
endmodule