Files
vortex/hw/rtl/VX_csr_data.v
Blaise Tine 43d8922f64 minor update
2020-04-21 15:21:59 -04:00

85 lines
2.6 KiB
Verilog

`include "VX_define.vh"
module VX_csr_data (
input wire clk, // Clock
input wire reset,
input wire[`CSR_ADDR_SIZE-1:0] read_csr_address,
input wire write_valid,
input wire[`CSR_WIDTH-1:0] write_csr_data,
`IGNORE_WARNINGS_BEGIN
// We use a smaller storage for CSRs than the standard 4KB in RISC-V
input wire[`CSR_ADDR_SIZE-1:0] write_csr_address,
`IGNORE_WARNINGS_END
output wire[31:0] read_csr_data,
// For instruction retire counting
input wire writeback_valid
);
// wire[`NUM_THREADS-1:0][31:0] thread_ids;
// wire[`NUM_THREADS-1:0][31:0] warp_ids;
// genvar cur_t;
// for (cur_t = 0; cur_t < `NUM_THREADS; cur_t = cur_t + 1) begin
// assign thread_ids[cur_t] = cur_t;
// end
// genvar cur_tw;
// for (cur_tw = 0; cur_tw < `NUM_THREADS; cur_tw = cur_tw + 1) begin
// assign warp_ids[cur_tw] = {{(31-`NW_BITS-1){1'b0}}, in_read_warp_num};
// end
reg [`CSR_WIDTH-1:0] csr[`NUM_CSRS-1:0];
reg [63:0] cycle;
reg [63:0] instret;
wire read_cycle;
wire read_cycleh;
wire read_instret;
wire read_instreth;
assign read_cycle = read_csr_address == `CSR_CYCL_L;
assign read_cycleh = read_csr_address == `CSR_CYCL_H;
assign read_instret = read_csr_address == `CSR_INST_L;
assign read_instreth = read_csr_address == `CSR_INST_H;
wire [$clog2(`NUM_CSRS)-1:0] read_addr, write_addr;
// cast address to physical CSR range
assign read_addr = $size(read_addr)'(read_csr_address);
assign write_addr = $size(write_addr)'(write_csr_address);
// wire thread_select = read_csr_address == 12'h20;
// wire warp_select = read_csr_address == 12'h21;
// assign read_csr_data = thread_select ? thread_ids :
// warp_select ? warp_ids :
// 0;
genvar curr_e;
always @(posedge clk) begin
if (reset) begin
cycle <= 0;
instret <= 0;
end else begin
cycle <= cycle + 1;
if (write_valid) begin
csr[write_addr] <= write_csr_data;
end
if (writeback_valid) begin
instret <= instret + 1;
end
end
end
assign read_csr_data = read_cycle ? cycle[31:0] :
read_cycleh ? cycle[63:32] :
read_instret ? instret[31:0] :
read_instreth ? instret[63:32] :
{{20{1'b0}}, csr[read_addr]};
endmodule : VX_csr_data