Files
vortex/rtl/cache/VX_d_cache.v
2019-10-25 03:03:09 -04:00

276 lines
9.3 KiB
Verilog

// Cache Memory (8way 4word) //
// i_ means input port //
// o_ means output port //
// _p_ means data exchange with processor //
// _m_ means data exchange with memory //
// TO DO:
// - Send in a response from memory of what the data is from the test bench
`include "../VX_define.v"
//`include "VX_priority_encoder.v"
// `include "VX_Cache_Bank.v"
//`include "cache_set.v"
module VX_d_cache(clk,
rst,
i_p_addr,
//i_p_byte_en,
i_p_writedata,
i_p_read_or_write, // 0 = Read | 1 = Write
i_p_valid,
//i_p_write,
o_p_readdata,
o_p_delay, // 0 = all threads done | 1 = Still threads that need to
o_m_evict_addr,
o_m_read_addr,
o_m_writedata,
o_m_read_or_write, // 0 = Read | 1 = Write
o_m_valid,
i_m_readdata,
i_m_ready
);
parameter NUMBER_BANKS = 8;
localparam CACHE_IDLE = 0; // Idle
localparam SEND_MEM_REQ = 1; // Write back this block into memory
localparam RECIV_MEM_RSP = 2;
//parameter cache_entry = 9;
input wire clk, rst;
input wire [`NT_M1:0] i_p_valid;
input wire [`NT_M1:0][31:0] i_p_addr; // FIXME
input wire [`NT_M1:0][31:0] i_p_writedata;
input wire i_p_read_or_write; //, i_p_write;
output reg [`NT_M1:0][31:0] o_p_readdata;
output wire o_p_delay;
output reg [31:0] o_m_evict_addr; // Address is xxxxxxxxxxoooobbbyy
output reg [31:0] o_m_read_addr;
output reg o_m_valid;
output reg[NUMBER_BANKS - 1:0][`NUM_WORDS_PER_BLOCK-1:0][31:0] o_m_writedata;
output reg o_m_read_or_write; //, o_m_write;
input wire[NUMBER_BANKS - 1:0][`NUM_WORDS_PER_BLOCK-1:0][31:0] i_m_readdata;
input wire i_m_ready;
// Buffer for final data
reg [`NT_M1:0][31:0] final_data_read;
reg [`NT_M1:0][31:0] new_final_data_read;
wire[`NT_M1:0][31:0] new_final_data_read_Qual;
assign o_p_readdata = new_final_data_read_Qual;
wire[NUMBER_BANKS - 1 : 0][`NT_M1:0] thread_track_banks; // Valid thread mask per bank
wire[NUMBER_BANKS - 1 : 0][$clog2(`NT)-1:0] index_per_bank; // Index of thread each bank will try to service
wire[NUMBER_BANKS - 1 : 0][`NT_M1:0] use_mask_per_bank; // A mask of index_per_bank
wire[NUMBER_BANKS - 1 : 0] valid_per_bank; // Valid request going to each bank
wire[NUMBER_BANKS - 1 : 0][`NT_M1:0] threads_serviced_per_bank; // Bank successfully serviced per bank
wire[NUMBER_BANKS-1:0][31:0] readdata_per_bank; // Data read from each bank
wire[NUMBER_BANKS-1:0] hit_per_bank; // Whether each bank got a hit or a miss
wire[NUMBER_BANKS-1:0] eviction_wb;
// Internal State
reg [3:0] state;
wire[3:0] new_state;
wire[`NT_M1:0] use_valid; // Valid used throught the code
reg[`NT_M1:0] stored_valid; // Saving the threads still left (bank conflict or bank miss)
wire[`NT_M1:0] new_stored_valid; // New stored valid
reg[NUMBER_BANKS - 1 : 0][31:0] eviction_addr_per_bank;
reg[31:0] miss_addr;
reg[31:0] evict_addr;
wire curr_processor_request_valid = (|i_p_valid);
assign use_valid = (stored_valid == 0) ? i_p_valid : stored_valid;
VX_cache_bank_valid #(.NUMBER_BANKS(NUMBER_BANKS)) multip_banks(
.i_p_valid (use_valid),
.i_p_addr (i_p_addr),
.thread_track_banks(thread_track_banks)
);
reg[`NT_M1:0] threads_serviced_Qual;
// reg detect_bank_conflict;
// genvar bank_ind;
// always @(*) begin
// for (bank_ind = 0; bank_ind < NUMBER_BANKS; bank_ind=bank_ind+1)
// begin
// detect_bank_conflict = detect_bank_conflict | ($countones(thread_track_banks[bank_ind]) > 1);
// end
// end
reg[`NT_M1:0] debug_hit_per_bank_mask[NUMBER_BANKS-1:0];
genvar bid;
for (bid = 0; bid < NUMBER_BANKS; bid=bid+1)
begin
wire[`NT_M1:0] use_threads_track_banks = thread_track_banks[bid];
wire[$clog2(`NT)-1:0] use_thread_index = index_per_bank[bid];
wire use_write_final_data = hit_per_bank[bid];
wire[31:0] use_data_final_data = readdata_per_bank[bid];
VX_priority_encoder_w_mask #(.N(`NT)) choose_thread(
.valids(use_threads_track_banks),
.mask (use_mask_per_bank[bid]),
.index (index_per_bank[bid]),
.found (valid_per_bank[bid])
);
always @(*) begin
if (use_write_final_data) new_final_data_read[use_thread_index] = use_data_final_data;
end
// assign new_final_data_read[use_thread_index] = use_write_final_data ? use_data_final_data : 0;
assign debug_hit_per_bank_mask[bid] = {`NT{hit_per_bank[bid]}};
assign threads_serviced_per_bank[bid] = use_mask_per_bank[bid] & debug_hit_per_bank_mask[bid];
end
wire[NUMBER_BANKS - 1 : 0] detect_bank_miss;
assign threads_serviced_Qual = threads_serviced_per_bank[0] | threads_serviced_per_bank[1] |
threads_serviced_per_bank[2] | threads_serviced_per_bank[3] |
threads_serviced_per_bank[4] | threads_serviced_per_bank[5] |
threads_serviced_per_bank[6] | threads_serviced_per_bank[7];
// genvar bbid;
// always @(*) begin
// for (bbid = 0; bbid < NUMBER_BANKS; bbid=bbid+1)
// begin
// assign threads_serviced_Qual = threads_serviced_Qual | threads_serviced_per_bank[bbid];
// end
// end
genvar tid;
for (tid = 0; tid < `NT; tid =tid+1)
begin
assign new_final_data_read_Qual[tid] = threads_serviced_Qual[tid] ? new_final_data_read[tid] : final_data_read[tid];
end
assign detect_bank_miss = (valid_per_bank & ~hit_per_bank);
wire delay;
assign delay = (new_stored_valid != 0) || (state != CACHE_IDLE); // add other states
assign o_p_delay = delay;
wire[NUMBER_BANKS - 1 : 0][$clog2(`NT)-1:0] send_index_to_bank = index_per_bank;
wire[$clog2(NUMBER_BANKS)-1:0] miss_bank_index;
wire miss_found;
VX_generic_priority_encoder #(.N(NUMBER_BANKS)) get_miss_index
(
.valids(detect_bank_miss),
.index (miss_bank_index),
.found (miss_found)
);
assign new_state = ((state == CACHE_IDLE) && (|detect_bank_miss)) ? SEND_MEM_REQ :
(state == SEND_MEM_REQ) ? RECIV_MEM_RSP :
((state == RECIV_MEM_RSP) && !i_m_ready) ? RECIV_MEM_RSP :
CACHE_IDLE;
// Handle if there is more than one miss
assign new_stored_valid = use_valid & (~threads_serviced_Qual);
genvar cur_t;
always @(posedge clk) begin
state <= new_state;
stored_valid <= new_stored_valid;
if (miss_found) begin
miss_addr <= i_p_addr[send_index_to_bank[miss_bank_index]];
evict_addr <= eviction_addr_per_bank[miss_bank_index];
end
final_data_read <= new_final_data_read_Qual;
end
genvar bank_id;
generate
for (bank_id = 0; bank_id < NUMBER_BANKS; bank_id = bank_id + 1)
begin
wire[31:0] bank_addr = (state == SEND_MEM_REQ) ? evict_addr :
(state == RECIV_MEM_RSP) ? miss_addr :
i_p_addr[send_index_to_bank[bank_id]];
wire[7:0] cache_index = bank_addr[14:7];
wire[16:0] cache_tag = bank_addr[31:15];
wire[1:0] cache_offset = bank_addr[6:5];
wire normal_valid_in = valid_per_bank[bank_id];
wire use_valid_in = ((state == RECIV_MEM_RSP) && i_m_ready) ? 1'b1 :
((state == RECIV_MEM_RSP) && !i_m_ready) ? 1'b0 :
((state == SEND_MEM_REQ)) ? 1'b0 :
normal_valid_in;
VX_Cache_Bank bank_structure (
.clk (clk),
.state (state),
.valid_in (use_valid_in),
.actual_index (cache_index),
.o_tag (cache_tag),
.block_offset (cache_offset),
.writedata (i_p_writedata[send_index_to_bank[bank_id]]),
.read_or_write (i_p_read_or_write),
.hit (hit_per_bank[bank_id]),
.readdata (readdata_per_bank[bank_id]), // Data read
.eviction_addr (eviction_addr_per_bank[bank_id]),
.data_evicted (o_m_writedata[bank_id]),
.eviction_wb (eviction_wb[bank_id]), // Something needs to be written back
.fetched_writedata(i_m_readdata[bank_id]) // Data From memory
);
end
endgenerate
// Mem Rsp
// Req to mem:
assign o_m_evict_addr = evict_addr & 32'hffffffc0;
assign o_m_read_addr = miss_addr & 32'hffffffc0;
assign o_m_valid = (state == SEND_MEM_REQ);
assign o_m_read_or_write = (state == SEND_MEM_REQ) && (|eviction_wb);
//end
endmodule