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kernels/hw/rtl/core/VX_scoreboard.sv
Blaise Tine a08d3ebd42 minor update
2023-11-12 23:40:59 -08:00

143 lines
5.9 KiB
Systemverilog

// Copyright © 2019-2023
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
`include "VX_define.vh"
module VX_scoreboard import VX_gpu_pkg::*; #(
parameter CORE_ID = 0
) (
input wire clk,
input wire reset,
VX_writeback_if.slave writeback_if [`ISSUE_WIDTH],
VX_ibuffer_if.slave ibuffer_if [`ISSUE_WIDTH],
VX_ibuffer_if.master scoreboard_if [`ISSUE_WIDTH]
);
`UNUSED_PARAM (CORE_ID)
localparam DATAW = `UUID_WIDTH + ISSUE_WIS_W + `NUM_THREADS + `XLEN + `EX_BITS + `INST_OP_BITS + `INST_MOD_BITS + 1 + 1 + `XLEN + (`NR_BITS * 4) + 1;
for (genvar i = 0; i < `ISSUE_WIDTH; ++i) begin
reg [`UP(ISSUE_RATIO)-1:0][`NUM_REGS-1:0] inuse_regs, inuse_regs_n;
reg [3:0] ready_masks, ready_masks_n;
VX_ibuffer_if staging_if();
wire writeback_fire = writeback_if[i].valid && writeback_if[i].data.eop;
always @(*) begin
inuse_regs_n = inuse_regs;
ready_masks_n = ready_masks;
if (writeback_fire) begin
inuse_regs_n[writeback_if[i].data.wis][writeback_if[i].data.rd] = 0;
ready_masks_n |= {4{(ISSUE_RATIO == 0) || writeback_if[i].data.wis == staging_if.data.wis}}
& {(writeback_if[i].data.rd == staging_if.data.rd),
(writeback_if[i].data.rd == staging_if.data.rs1),
(writeback_if[i].data.rd == staging_if.data.rs2),
(writeback_if[i].data.rd == staging_if.data.rs3)};
end
if (staging_if.valid && staging_if.ready && staging_if.data.wb) begin
inuse_regs_n[staging_if.data.wis][staging_if.data.rd] = 1;
ready_masks_n = '0;
end
if (ibuffer_if[i].valid && ibuffer_if[i].ready) begin
ready_masks_n = ~{inuse_regs_n[ibuffer_if[i].data.wis][ibuffer_if[i].data.rd],
inuse_regs_n[ibuffer_if[i].data.wis][ibuffer_if[i].data.rs1],
inuse_regs_n[ibuffer_if[i].data.wis][ibuffer_if[i].data.rs2],
inuse_regs_n[ibuffer_if[i].data.wis][ibuffer_if[i].data.rs3]};
end
end
always @(posedge clk) begin
if (reset) begin
inuse_regs <= '0;
ready_masks <= '0;
end else begin
inuse_regs <= inuse_regs_n;
ready_masks <= ready_masks_n;
end
end
// staging buffer
`RESET_RELAY (stg_buf_reset, reset);
VX_elastic_buffer #(
.DATAW (DATAW)
) stg_buf (
.clk (clk),
.reset (stg_buf_reset),
.valid_in (ibuffer_if[i].valid),
.ready_in (ibuffer_if[i].ready),
.data_in (ibuffer_if[i].data),
.data_out (staging_if.data),
.valid_out (staging_if.valid),
.ready_out (staging_if.ready)
);
// output buffer
wire valid_stg, ready_stg;
wire regs_ready = (& ready_masks);
assign valid_stg = staging_if.valid && regs_ready;
assign staging_if.ready = ready_stg && regs_ready;
`RESET_RELAY (out_buf_reset, reset);
VX_elastic_buffer #(
.DATAW (DATAW),
.SIZE (2),
.OUT_REG (2)
) out_buf (
.clk (clk),
.reset (out_buf_reset),
.valid_in (valid_stg),
.ready_in (ready_stg),
.data_in (staging_if.data),
.data_out (scoreboard_if[i].data),
.valid_out (scoreboard_if[i].valid),
.ready_out (scoreboard_if[i].ready)
);
`ifdef SIMULATION
reg [31:0] timeout_ctr;
always @(posedge clk) begin
if (reset) begin
timeout_ctr <= '0;
end else begin
if (staging_if.valid && ~regs_ready) begin
`ifdef DBG_TRACE_CORE_PIPELINE
`TRACE(3, ("%d: *** core%0d-scoreboard-stall: wid=%0d, PC=0x%0h, tmask=%b, cycles=%0d, inuse=%b (#%0d)\n",
$time, CORE_ID, wis_to_wid(staging_if.data.wis, i), staging_if.data.PC, staging_if.data.tmask, timeout_ctr,
~ready_masks, staging_if.data.uuid));
`endif
timeout_ctr <= timeout_ctr + 1;
end else if (staging_if.valid && staging_if.ready) begin
timeout_ctr <= '0;
end
end
end
`RUNTIME_ASSERT((timeout_ctr < `STALL_TIMEOUT),
("%t: *** core%0d-scoreboard-timeout: wid=%0d, PC=0x%0h, tmask=%b, cycles=%0d, inuse=%b (#%0d)",
$time, CORE_ID, wis_to_wid(staging_if.data.wis, i), staging_if.data.PC, staging_if.data.tmask, timeout_ctr,
~ready_masks, staging_if.data.uuid));
`RUNTIME_ASSERT(~writeback_fire || inuse_regs[writeback_if[i].data.wis][writeback_if[i].data.rd] != 0,
("%t: *** core%0d: invalid writeback register: wid=%0d, PC=0x%0h, tmask=%b, rd=%0d (#%0d)",
$time, CORE_ID, wis_to_wid(writeback_if[i].data.wis, i), writeback_if[i].data.PC, writeback_if[i].data.tmask, writeback_if[i].data.rd, writeback_if[i].data.uuid));
`endif
end
endmodule