Files
kernels/hw/rtl/generic_cache/VX_cache_dram_req_arb.v
2020-04-16 10:22:46 -04:00

151 lines
5.2 KiB
Verilog

`include "VX_cache_config.vh"
module VX_cache_dram_req_arb
#(
// Size of cache in bytes
parameter CACHE_SIZE_BYTES = 1024,
// Size of line inside a bank in bytes
parameter BANK_LINE_SIZE_BYTES = 16,
// Number of banks {1, 2, 4, 8,...}
parameter NUM_BANKS = 8,
// Size of a word in bytes
parameter WORD_SIZE_BYTES = 4,
// Number of Word requests per cycle {1, 2, 4, 8, ...}
parameter NUM_REQUESTS = 2,
// Number of cycles to complete stage 1 (read from memory)
parameter STAGE_1_CYCLES = 2,
// Queues feeding into banks Knobs {1, 2, 4, 8, ...}
// Core Request Queue Size
parameter REQQ_SIZE = 8,
// Miss Reserv Queue Knob
parameter MRVQ_SIZE = 8,
// Dram Fill Rsp Queue Size
parameter DFPQ_SIZE = 2,
// Snoop Req Queue
parameter SNRQ_SIZE = 8,
// Queues for writebacks Knobs {1, 2, 4, 8, ...}
// Core Writeback Queue Size
parameter CWBQ_SIZE = 8,
// Dram Writeback Queue Size
parameter DWBQ_SIZE = 4,
// Dram Fill Req Queue Size
parameter DFQQ_SIZE = 8,
// Lower Level Cache Hit Queue Size
parameter LLVQ_SIZE = 16,
// Fill Invalidator Size {Fill invalidator must be active}
parameter FILL_INVALIDAOR_SIZE = 16,
// Prefetcher
parameter PRFQ_SIZE = 64,
parameter PRFQ_STRIDE = 2,
// Dram knobs
parameter SIMULATED_DRAM_LATENCY_CYCLES = 10
)
(
input wire clk,
input wire reset,
// Fill Request
output wire dfqq_full,
input wire[NUM_BANKS-1:0] per_bank_dram_fill_req,
input wire[NUM_BANKS-1:0][31:0] per_bank_dram_fill_req_addr,
// DFQ Request
output wire[NUM_BANKS-1:0] per_bank_dram_wb_queue_pop,
input wire[NUM_BANKS-1:0] per_bank_dram_wb_req,
input wire[NUM_BANKS-1:0][31:0] per_bank_dram_wb_req_addr,
input wire[NUM_BANKS-1:0][`BANK_LINE_WORDS-1:0][`WORD_SIZE-1:0] per_bank_dram_wb_req_data,
input wire[NUM_BANKS-1:0] per_bank_dram_because_of_snp,
// real Dram request
output wire dram_req,
output wire dram_req_write,
output wire dram_req_read,
output wire [31:0] dram_req_addr,
output wire [31:0] dram_req_size,
output wire [`IBANK_LINE_WORDS-1:0][31:0] dram_req_data,
output wire dram_req_because_of_wb,
input wire dram_req_delay
);
wire pref_pop;
wire pref_valid;
wire[31:0] pref_addr;
wire dwb_valid;
wire dfqq_req;
assign pref_pop = !dwb_valid && !dfqq_req && !dram_req_delay && pref_valid;
VX_prefetcher #(
.PRFQ_SIZE (PRFQ_SIZE),
.PRFQ_STRIDE (PRFQ_STRIDE),
.BANK_LINE_SIZE_BYTES(BANK_LINE_SIZE_BYTES),
.WORD_SIZE_BYTES (WORD_SIZE_BYTES)
)
prfqq
(
.clk (clk),
.reset (reset),
.dram_req (dram_req && dram_req_read),
.dram_req_addr(dram_req_addr),
.pref_pop (pref_pop),
.pref_valid (pref_valid),
.pref_addr (pref_addr)
);
wire[31:0] dfqq_req_addr;
wire dfqq_empty;
wire dfqq_pop = !dwb_valid && dfqq_req && !dram_req_delay; // If no dwb, and dfqq has valids, then pop
wire dfqq_push = (|per_bank_dram_fill_req);
VX_cache_dfq_queue VX_cache_dfq_queue(
.clk (clk),
.reset (reset),
.dfqq_push (dfqq_push),
.per_bank_dram_fill_req (per_bank_dram_fill_req),
.per_bank_dram_fill_req_addr(per_bank_dram_fill_req_addr),
.dfqq_pop (dfqq_pop),
.dfqq_req (dfqq_req),
.dfqq_req_addr (dfqq_req_addr),
.dfqq_empty (dfqq_empty),
.dfqq_full (dfqq_full)
);
wire[`LOG2UP(NUM_BANKS)-1:0] dwb_bank;
// wire[NUM_BANKS-1:0] use_wb_valid = per_bank_dram_wb_req | per_bank_dram_because_of_snp;
wire[NUM_BANKS-1:0] use_wb_valid = per_bank_dram_wb_req;
VX_generic_priority_encoder #(.N(NUM_BANKS)) VX_sel_dwb(
.valids(use_wb_valid),
.index (dwb_bank),
.found (dwb_valid)
);
assign per_bank_dram_wb_queue_pop = dram_req_delay ? 0 : use_wb_valid & ((1 << dwb_bank));
assign dram_req = dwb_valid || dfqq_req || pref_pop;
assign dram_req_write = dwb_valid && dram_req;
assign dram_req_read = ((dfqq_req && !dwb_valid) || pref_pop) && dram_req;
assign dram_req_addr = (dwb_valid ? per_bank_dram_wb_req_addr[dwb_bank] : (dfqq_req ? dfqq_req_addr : pref_addr)) & `BASE_ADDR_MASK;
assign dram_req_size = BANK_LINE_SIZE_BYTES;
assign {dram_req_data} = dwb_valid ? {per_bank_dram_wb_req_data[dwb_bank] }: 0;
// assign dram_req_because_of_wb = dwb_valid ? per_bank_dram_because_of_snp[dwb_bank] : 0;
assign dram_req_because_of_wb = 0;
endmodule