Files
vortex/rtl/cache/VX_Cache_Bank.v
2019-10-24 10:38:04 -04:00

134 lines
3.9 KiB
Verilog

// To Do: Change way_id_out to an internal register which holds when in between access and finished.
// Also add a bit about wheter the "Way ID" is valid / being held or if it is just default
// Also make sure all possible output states are transmitted back to the bank correctly
`define NUM_WORDS_PER_BLOCK 4
`include "../VX_define.v"
`include "VX_cache_data.v"
module VX_Cache_Bank
#(
// parameter NUMBER_INDEXES = 256
parameter NUMBER_INDEXES = 256
)
(
clk,
state,
read_or_write, // Read = 0 | Write = 1
valid_in,
//write_from_mem,
actual_index,
o_tag,
block_offset,
writedata,
fetched_writedata,
readdata,
hit,
//miss,
eviction_wb, // Need to evict
eviction_addr, // What's the eviction tag
data_evicted
);
parameter cache_entry = 14;
parameter ways_per_set = 4;
parameter Number_Blocks = 32;
localparam CACHE_IDLE = 0; // Idle
localparam SEND_MEM_REQ = 1; // Write back this block into memory
localparam RECIV_MEM_RSP = 2;
// Inputs
input wire clk;
input wire [3:0] state;
//input wire write_from_mem;
// Reading Data
input wire[$clog2(NUMBER_INDEXES)-1:0] actual_index;
input wire[16:0] o_tag; // When write_from_mem = 1, o_tag is the new tag
input wire[1:0] block_offset;
input wire[31:0] writedata;
input wire valid_in;
input wire read_or_write; // Specifies if it is a read or write operation
input wire[`NUM_WORDS_PER_BLOCK-1:0][31:0] fetched_writedata;
// Outputs
// Normal shit
output wire[31:0] readdata;
output wire hit;
//output wire miss;
// Eviction Data (Notice)
output wire eviction_wb; // Need to evict
output wire[31:0] eviction_addr; // What's the eviction tag
// Eviction Data (Extraction)
output wire[`NUM_WORDS_PER_BLOCK-1:0][31:0] data_evicted;
wire[`NUM_WORDS_PER_BLOCK-1:0][31:0] data_use;
wire[16:0] tag_use;
wire[16:0] eviction_tag;
wire valid_use;
wire dirty_use;
wire access;
wire write_from_mem;
wire miss; // -10/21
assign miss = (tag_use != o_tag) && valid_use && valid_in;
assign data_evicted = data_use;
assign eviction_wb = miss && (dirty_use != 1'b0);
assign eviction_tag = tag_use;
assign access = (state == CACHE_IDLE) && valid_in;
assign write_from_mem = (state == RECIV_MEM_RSP) && valid_in;
assign readdata = (access) ? data_use[block_offset] : 32'b0; // Fix with actual data
assign hit = (access && (tag_use == o_tag) && valid_use);
//assign eviction_addr = {eviction_tag, actual_index, block_offset, 5'b0}; // Fix with actual data
assign eviction_addr = {eviction_tag, actual_index, 7'b0}; // Fix with actual data
wire[`NUM_WORDS_PER_BLOCK-1:0] we;
wire[`NUM_WORDS_PER_BLOCK-1:0][31:0] data_write;
genvar g;
for (g = 0; g < `NUM_WORDS_PER_BLOCK; g = g + 1) begin
wire correct_block = (block_offset == g);
assign we[g] = (read_or_write && ((access && correct_block) || (write_from_mem && !correct_block)) ) ? 1'b1 : 1'b0;
//assign we[g] = (!(write_from_mem && correct_block) && ((write_from_mem || correct_block) && read_or_write == 1'b1)) ? 1 : 0; // added the "not"
assign data_write[g] = write_from_mem ? fetched_writedata[g] : writedata;
end
VX_cache_data data_structures(
.clk (clk),
// Inputs
.addr (actual_index),
.we (we),
.evict (write_from_mem),
.data_write(data_write),
.tag_write (o_tag),
// Outputs
.tag_use (tag_use),
.data_use (data_use),
.valid_use (valid_use),
.dirty_use (dirty_use)
);
endmodule