Files
kernels/rtl/cache/VX_Cache_Block_DM.v
2019-10-22 06:02:08 -04:00

196 lines
6.3 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.v"
module VX_Cache_Block_DM(clk,
rst,
// These next 4 are possible modes that the Set could be in, I am making them 4 different variables for indexing purposes
access, // First
find_evict,
write_from_mem,
idle,
// entry,
o_tag,
block_offset,
writedata,
//byte_en,
write,
fetched_writedata,
//word_en,
//way_id_in,
//way_id_out,
readdata,
//wb_addr,
hit,
eviction_wb,
eviction_tag,
evicted_data,
//modify,
miss
//valid_data
//read_miss
);
parameter cache_entry = 14;
parameter ways_per_set = 4;
parameter Number_Blocks = 32;
input wire clk, rst;
input wire access;
input wire find_evict;
input wire write_from_mem;
input wire idle;
//input wire [cache_entry-1:0] entry;
input wire [21:0] o_tag;
input wire [4:0] block_offset;
input wire [31:0] writedata;
//input wire [3:0] byte_en;
input wire write; // 0 == False
input wire [31:0][31:0] fetched_writedata;
//input wire [3:0] word_en;
//input wire read_miss;
//input wire [1:0] way_id_in;
//output reg [1:0] way_id_out;
//output reg [31:0] readdata;
output wire [31:0] readdata;
//output reg hit;
output wire hit;
output reg miss;
output wire eviction_wb;
output wire [21:0] eviction_tag;
output wire [31:0][31:0] evicted_data;
//reg [31:0] eviction_data;
//output wire [22:0] wb_addr;
//output wire modify, valid_data;
//wire [2:0] i_tag;
//wire dirty;
//wire [24-cache_entry:0] write_tag_data;
// Table for one set
//reg [2:0] counter; // Determines which to evict
reg valid;
reg [21:0] tag;
reg clean;
//reg [31:0] data[31:0];
reg [31:0] data[31:0];
integer j;
// WS AW BS
//reg[3:0][31:0] some_data[5:0]; // before variable name is width, after name is height
//wire blockNun;
//wire WordNumWIthinABlock;
//ddata[31:0] =some_data[blockNun][WordNumWIthinABlock]
assign eviction_wb = miss && clean != 1'b1 && valid == 1'b1;
assign eviction_tag = tag;
assign readdata = (access && !write && tag == o_tag && valid) ? data[0] : 32'b0; // Fix with actual data
assign hit = (access && !write && tag == o_tag && valid) ? 1'b1 : 1'b0;
//assign evicted_data = (eviction_wb ) ? data : 0;
genvar k;
for (k = 0; k < Number_Blocks; k = k + 1) begin
assign evicted_data[k] = (eviction_wb) ? data[k] : 32'b0;
//data[j] <= fetched_writedata[(j+1) * 32 - 1 -: 32];
end
//assign eviction_data = data[counter[1:0]];
//assign hit = valid_data && (o_tag == i_tag);
//assign modify = valid_data && (o_tag != i_tag) && dirty;
//assign miss = !valid_data || ((o_tag != i_tag) && !dirty);
//assign wb_addr = {i_tag, entry};
always @(posedge clk) begin
if (rst) begin
end
if (find_evict) begin
if (tag == o_tag && valid) begin
//readdata <= data;
// evicted_data <= data;
end
end else if (access) begin
// Hit in First Column
if (tag == o_tag && valid) begin
if (write == 1'b0) begin // if it is a read
if (clean == 1'b1 ) begin
//hit <= 1'b1;
//readdata <= data;
miss <= 1'b0;
end else begin
//hit <= 1'b0;
//readdata <= 32'b0;
miss <= 1'b1;
end
end else if (write == 1'b1) begin
//for (j = 0; j < Number_Blocks; j = j + 1) begin
//data[j] <= fetched_writedata[(j+1) * 32 - 1 -: 32];
//end
data[block_offset] <= writedata;
clean <= 1'b0;
//hit <= 1'b1;
end
end
// Miss
else begin
//way_id_out <= counter;
miss <= 1'b1;
if (write == 1'b0) begin // Read Miss
clean <= 1'b1;
//data <= 0; // FIX WITH ACTUAL MEMORY ACCESS
for (j = 0; j < Number_Blocks; j = j + 1) begin
data[j] <= 32'b0;
end
end else if (write == 1'b1) begin // Write Miss
clean <= 1'b1;
data[block_offset] <= writedata;
//for (j = 0; j < Number_Blocks; j = j + 1) begin
//data[j] <= fetched_writedata[(j+1) * 32 - 1 -: 32];
//end
end
end
end
if (write_from_mem) begin
tag <= o_tag;
valid <= 1'b1;
//hit <= 1'b1;
if (write == 1'b0) begin // Read Miss
clean <= 1'b1;
//data <= 0; // FIX WITH ACTUAL MEMORY ACCESS
for (j = 0; j < Number_Blocks; j = j + 1) begin
data[j] <= 32'b0;
end
end else if (write == 1'b1) begin // Write Miss
clean <= 1'b0;
//data <= fetched_writedata;
for (j = 0; j < Number_Blocks; j = j + 1) begin
//data[j] <= fetched_writedata[(j+1) * 32 - 1 -: 32];
data[j] <= fetched_writedata[j];
end
end
end
if (idle) begin // Set "way" register equal to invalid value
//hit <= 1'b1; // set to know it is ready
miss <= 1'b0;
//readdata <= 32'hFFFFFFFF;
end
if (find_evict) begin // Keep "way" value the same !!!! Fix. Need to send back data with matching tag. Also need to ensure evicted data doesnt get lost
if (tag == o_tag && valid) begin
//readdata <= data;
end
//hit <= 1'b1;
miss <= 1'b0;
end
//eviction_data <= data;
end
endmodule