Files
vortex/hw/rtl/VX_scoreboard.v
2020-12-05 01:40:50 -08:00

91 lines
3.6 KiB
Verilog

`include "VX_define.vh"
module VX_scoreboard #(
parameter CORE_ID = 0
) (
input wire clk,
input wire reset,
VX_decode_if ibuf_deq_if,
VX_writeback_if writeback_if,
input wire [`NW_BITS-1:0] deq_wid_next,
input wire exe_delay,
output wire delay
);
reg [`NUM_THREADS-1:0] inuse_registers [(`NUM_WARPS * `NUM_REGS)-1:0];
reg [`NUM_WARPS-1:0][`NUM_REGS-1:0] inuse_reg_mask, inuse_reg_mask_n;
reg [`NUM_REGS-1:0] deq_used_regs;
wire [`NUM_REGS-1:0] inuse_regs = deq_used_regs & ibuf_deq_if.used_regs;
assign delay = (| inuse_regs);
wire reserve_reg = ibuf_deq_if.valid && ibuf_deq_if.ready && (ibuf_deq_if.wb != 0);
wire release_reg = writeback_if.valid && writeback_if.ready;
wire [`NUM_THREADS-1:0] inuse_registers_n = inuse_registers[{writeback_if.wid, writeback_if.rd}] & ~writeback_if.tmask;
always @(*) begin
inuse_reg_mask_n = inuse_reg_mask;
if (reserve_reg) begin
inuse_reg_mask_n[ibuf_deq_if.wid][ibuf_deq_if.rd] = 1;
end
if (release_reg) begin
inuse_reg_mask_n[writeback_if.wid][writeback_if.rd] = (| inuse_registers_n);
end
end
always @(posedge clk) begin
if (reset) begin
for (integer w = 0; w < `NUM_WARPS; w++) begin
for (integer i = 0; i < `NUM_REGS; i++) begin
inuse_registers[w * `NUM_REGS + i] <= 0;
end
inuse_reg_mask[w] <= `NUM_REGS'(0);
end
end else begin
if (reserve_reg) begin
inuse_registers[{ibuf_deq_if.wid, ibuf_deq_if.rd}] <= ibuf_deq_if.tmask;
end
if (release_reg) begin
assert(inuse_reg_mask[writeback_if.wid][writeback_if.rd] != 0)
else $error("*** %t: core%0d: invalid writeback register: wid=%0d, PC=%0h, rd=%0d",
$time, CORE_ID, writeback_if.wid, writeback_if.PC, writeback_if.rd);
inuse_registers[{writeback_if.wid, writeback_if.rd}] <= inuse_registers_n;
end
inuse_reg_mask <= inuse_reg_mask_n;
end
deq_used_regs <= inuse_reg_mask_n[deq_wid_next];
end
// issue the instruction
assign ibuf_deq_if.ready = ~(delay || exe_delay);
`ifdef DBG_PRINT_PIPELINE
always @(posedge clk) begin
if (ibuf_deq_if.valid && ~ibuf_deq_if.ready) begin
$display("%t: core%0d-stall: wid=%0d, PC=%0h, rd=%0d, wb=%0d, inuse=%b%b%b%b, exe=%b",
$time, CORE_ID, ibuf_deq_if.wid, ibuf_deq_if.PC, ibuf_deq_if.rd, ibuf_deq_if.wb,
inuse_regs[ibuf_deq_if.rd], inuse_regs[ibuf_deq_if.rs1], inuse_regs[ibuf_deq_if.rs2], inuse_regs[ibuf_deq_if.rs3], exe_delay);
end
end
`endif
reg [31:0] stall_ctr;
always @(posedge clk) begin
if (reset) begin
stall_ctr <= 0;
end else if (ibuf_deq_if.valid && ~ibuf_deq_if.ready) begin
stall_ctr <= stall_ctr + 1;
assert(stall_ctr < 100000) else $error("*** %t: core%0d-stalled: wid=%0d, PC=%0h, rd=%0d, wb=%0d, inuse=%b%b%b%b, exe=%b",
$time, CORE_ID, ibuf_deq_if.wid, ibuf_deq_if.PC, ibuf_deq_if.rd, ibuf_deq_if.wb,
inuse_regs[ibuf_deq_if.rd], inuse_regs[ibuf_deq_if.rs1], inuse_regs[ibuf_deq_if.rs2], inuse_regs[ibuf_deq_if.rs3], exe_delay);
end else if (ibuf_deq_if.valid && ibuf_deq_if.ready) begin
stall_ctr <= 0;
end
end
endmodule