Files
vortex/hw/rtl/cache/VX_Cache_Bank.v
2020-04-16 07:49:19 -04:00

254 lines
8.4 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
`include "VX_define.vh"
module VX_Cache_Bank
#(
parameter CACHE_SIZE = 4096, // Bytes
parameter CACHE_WAYS = 1,
parameter CACHE_BLOCK = 128, // Bytes
parameter CACHE_BANKS = 8,
parameter LOG_NUM_BANKS = 3,
parameter NUM_REQ = 8,
parameter LOG_NUM_REQ = 3,
parameter NUM_IND = 8,
parameter CACHE_WAY_INDEX = 1,
parameter NUM_WORDS_PER_BLOCK = 4,
parameter OFFSET_SIZE_START = 0,
parameter OFFSET_SIZE_END = 1,
parameter TAG_SIZE_START = 0,
parameter TAG_SIZE_END = 16,
parameter IND_SIZE_START = 0,
parameter IND_SIZE_END = 7,
parameter ADDR_TAG_START = 15,
parameter ADDR_TAG_END = 31,
parameter ADDR_OFFSET_START = 5,
parameter ADDR_OFFSET_END = 6,
parameter ADDR_IND_START = 7,
parameter ADDR_IND_END = 14
)
(
clk,
rst,
state,
read_or_write, // Read = 0 | Write = 1
i_p_mem_read,
i_p_mem_write,
valid_in,
//write_from_mem,
actual_index,
o_tag,
block_offset,
writedata,
fetched_writedata,
byte_select,
readdata,
hit,
//miss,
eviction_wb, // Need to evict
eviction_addr, // What's the eviction tag
data_evicted,
evicted_way
);
// localparam NUMBER_BANKS = `CACHE_BANKS;
// localparam CACHE_BLOCK_PER_BANK = (`CACHE_BLOCK / `CACHE_BANKS);
// localparam NUM_WORDS_PER_BLOCK = `CACHE_BLOCK / (`CACHE_BANKS*4);
// localparam NUMBER_INDEXES = `NUM_IND;
localparam CACHE_IDLE = 0; // Idle
localparam SEND_MEM_REQ = 1; // Write back this block into memory
localparam RECIV_MEM_RSP = 2;
localparam BLOCK_NUM_BITS = `LOG2UP(CACHE_BLOCK);
// Inputs
input wire rst;
input wire clk;
input wire [3:0] state;
//input wire write_from_mem;
// Reading Data
input wire[IND_SIZE_END:IND_SIZE_START] actual_index;
input wire[TAG_SIZE_END:TAG_SIZE_START] o_tag; // When write_from_mem = 1, o_tag is the new tag
input wire[OFFSET_SIZE_END:OFFSET_SIZE_START] 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;
input wire[2:0] i_p_mem_read;
input wire[2:0] i_p_mem_write;
input wire[1:0] byte_select;
input wire[CACHE_WAY_INDEX-1:0] evicted_way;
// 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[TAG_SIZE_END:TAG_SIZE_START] tag_use;
wire[TAG_SIZE_END:TAG_SIZE_START] eviction_tag;
wire valid_use;
wire dirty_use;
wire access;
wire write_from_mem;
wire miss; // -10/21
wire[CACHE_WAY_INDEX-1:0] way_to_update;
assign miss = (tag_use != o_tag) && valid_use && valid_in;
assign data_evicted = data_use;
// assign eviction_wb = miss && (dirty_use != 1'b0) && valid_use;
assign eviction_wb = (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; // TODO
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, {(BLOCK_NUM_BITS){1'b0}}}; // Fix with actual data
wire lw = (i_p_mem_read == `LW_MEM_READ);
wire lb = (i_p_mem_read == `LB_MEM_READ);
wire lh = (i_p_mem_read == `LH_MEM_READ);
wire lhu = (i_p_mem_read == `LHU_MEM_READ);
wire lbu = (i_p_mem_read == `LBU_MEM_READ);
wire sw = (i_p_mem_write == `SW_MEM_WRITE);
wire sb = (i_p_mem_write == `SB_MEM_WRITE);
wire sh = (i_p_mem_write == `SH_MEM_WRITE);
wire b0 = (byte_select == 0);
wire b1 = (byte_select == 1);
wire b2 = (byte_select == 2);
wire b3 = (byte_select == 3);
wire[31:0] data_unQual = (b0 || lw) ? (data_use[block_offset] ) :
b1 ? (data_use[block_offset] >> 8) :
b2 ? (data_use[block_offset] >> 16) :
(data_use[block_offset] >> 24);
wire[31:0] lb_data = (data_unQual[7] ) ? (data_unQual | 32'hFFFFFF00) : (data_unQual & 32'hFF);
wire[31:0] lh_data = (data_unQual[15]) ? (data_unQual | 32'hFFFF0000) : (data_unQual & 32'hFFFF);
wire[31:0] lbu_data = (data_unQual & 32'hFF);
wire[31:0] lhu_data = (data_unQual & 32'hFFFF);
wire[31:0] lw_data = (data_unQual);
wire[31:0] sw_data = writedata;
wire[31:0] sb_data = b1 ? {{16{1'b0}}, writedata[7:0], { 8{1'b0}}} :
b2 ? {{ 8{1'b0}}, writedata[7:0], {16{1'b0}}} :
b3 ? {{ 0{1'b0}}, writedata[7:0], {24{1'b0}}} :
writedata;
wire[31:0] sh_data = b2 ? {writedata[15:0], {16{1'b0}}} : writedata;
wire[31:0] use_write_data = sb ? sb_data :
sh ? sh_data :
sw_data;
wire[31:0] data_Qual = lb ? lb_data :
lh ? lh_data :
lhu ? lhu_data :
lbu ? lbu_data :
lw_data;
assign readdata = (access) ? data_Qual : 32'b0; // Fix with actual data
wire[3:0] sb_mask = (b0 ? 4'b0001 : (b1 ? 4'b0010 : (b2 ? 4'b0100 : 4'b1000)));
wire[3:0] sh_mask = (b0 ? 4'b0011 : 4'b1100);
wire[NUM_WORDS_PER_BLOCK-1:0][3:0] we;
wire[NUM_WORDS_PER_BLOCK-1:0][31:0] data_write;
genvar g;
generate
for (g = 0; g < NUM_WORDS_PER_BLOCK; g = g + 1) begin : write_enables
wire normal_write = (read_or_write && ((access && (block_offset == g))) && !miss);
assign we[g] = (write_from_mem) ? 4'b1111 :
(normal_write && sw) ? 4'b1111 :
(normal_write && sb) ? sb_mask :
(normal_write && sh) ? sh_mask :
4'b0000;
// assign we[g] = (normal_write || (write_from_mem)) ? 1'b1 : 1'b0;
assign data_write[g] = write_from_mem ? fetched_writedata[g] : use_write_data;
assign way_to_update = evicted_way;
end
endgenerate
VX_cache_data_per_index #(
.CACHE_WAYS (CACHE_WAYS),
.NUM_IND (NUM_IND),
.CACHE_WAY_INDEX (CACHE_WAY_INDEX),
.NUM_WORDS_PER_BLOCK(NUM_WORDS_PER_BLOCK),
.TAG_SIZE_START (TAG_SIZE_START),
.TAG_SIZE_END (TAG_SIZE_END),
.IND_SIZE_START (IND_SIZE_START),
.IND_SIZE_END (IND_SIZE_END)) data_structures(
.clk (clk),
.rst (rst),
.valid_in (valid_in),
.state (state),
// Inputs
.addr (actual_index),
.we (we),
.evict (write_from_mem),
.data_write (data_write),
.tag_write (o_tag),
.way_to_update(way_to_update),
// Outputs
.tag_use (tag_use),
.data_use (data_use),
.valid_use (valid_use),
.dirty_use (dirty_use)
);
endmodule