Files
vortex/hw/rtl/VX_csr_unit.v
2020-08-14 21:50:14 -07:00

115 lines
3.8 KiB
Verilog

`include "VX_define.vh"
module VX_csr_unit #(
parameter CORE_ID = 0
) (
input wire clk,
input wire reset,
VX_cmt_to_csr_if cmt_to_csr_if,
VX_csr_to_fpu_if csr_to_fpu_if,
VX_csr_io_req_if csr_io_req_if,
VX_csr_io_rsp_if csr_io_rsp_if,
VX_csr_req_if csr_req_if,
VX_exu_to_cmt_if csr_commit_if
);
VX_csr_req_if csr_pipe_req_if();
VX_csr_rsp_if csr_pipe_rsp_if();
wire select_io_req = csr_io_req_if.valid;
wire select_io_rsp;
VX_csr_arb csr_arb (
.clk (clk),
.reset (reset),
.csr_core_req_if (csr_req_if),
.csr_io_req_if (csr_io_req_if),
.csr_req_if (csr_pipe_req_if),
.csr_rsp_if (csr_pipe_rsp_if),
.csr_io_rsp_if (csr_io_rsp_if),
.csr_commit_if (csr_commit_if),
.select_io_req (select_io_req),
.select_io_rsp (select_io_rsp)
);
wire csr_we_s1;
wire [`CSR_ADDR_BITS-1:0] csr_addr_s1;
wire [31:0] csr_read_data, csr_read_data_s1;
wire [31:0] csr_updated_data_s1;
wire [`NW_BITS-1:0] wid_s1;
VX_csr_data #(
.CORE_ID(CORE_ID)
) csr_data (
.clk (clk),
.reset (reset),
.cmt_to_csr_if (cmt_to_csr_if),
.csr_to_fpu_if (csr_to_fpu_if),
.read_enable (csr_pipe_req_if.valid),
.read_addr (csr_pipe_req_if.csr_addr),
.read_data (csr_read_data),
.write_enable (csr_we_s1),
.write_data (csr_updated_data_s1[`CSR_WIDTH-1:0]),
.write_addr (csr_addr_s1),
.wid (csr_pipe_req_if.wid)
);
wire csr_hazard = (csr_addr_s1 == csr_pipe_req_if.csr_addr)
&& (wid_s1 == csr_pipe_req_if.wid)
&& csr_pipe_rsp_if.valid;
wire [31:0] csr_read_data_qual = csr_hazard ? csr_updated_data_s1 : csr_read_data;
reg [31:0] csr_updated_data;
reg csr_we_s0_unqual;
always @(*) begin
csr_we_s0_unqual = 0;
case (csr_pipe_req_if.op)
`CSR_RW: begin
csr_updated_data = csr_pipe_req_if.csr_mask;
csr_we_s0_unqual = 1;
end
`CSR_RS: begin
csr_updated_data = csr_read_data_qual | csr_pipe_req_if.csr_mask;
csr_we_s0_unqual = (csr_pipe_req_if.csr_mask != 0);
end
`CSR_RC: begin
csr_updated_data = csr_read_data_qual & (32'hFFFFFFFF - csr_pipe_req_if.csr_mask);
csr_we_s0_unqual = (csr_pipe_req_if.csr_mask != 0);
end
default: csr_updated_data = 32'hdeadbeef;
endcase
end
wire csr_we_s0 = csr_we_s0_unqual && csr_pipe_req_if.valid;
wire stall = ~csr_pipe_rsp_if.ready && csr_pipe_rsp_if.valid;
VX_generic_register #(
.N(1 + `ISTAG_BITS + `NW_BITS + 1 + `CSR_ADDR_BITS + 1 + 32 + 32)
) csr_reg (
.clk (clk),
.reset (reset),
.stall (stall),
.flush (0),
.in ({csr_pipe_req_if.valid, csr_pipe_req_if.issue_tag, csr_pipe_req_if.wid, csr_we_s0, csr_pipe_req_if.csr_addr, csr_pipe_req_if.is_io, csr_read_data_qual, csr_updated_data}),
.out ({csr_pipe_rsp_if.valid, csr_pipe_rsp_if.issue_tag, wid_s1, csr_we_s1, csr_addr_s1, select_io_rsp, csr_read_data_s1, csr_updated_data_s1})
);
for (genvar i = 0; i < `NUM_THREADS; i++) begin
assign csr_pipe_rsp_if.data[i] = (csr_addr_s1 == `CSR_LTID) ? i :
(csr_addr_s1 == `CSR_GTID) ? (csr_read_data_s1 * `NUM_THREADS + i) :
csr_read_data_s1;
end
assign csr_pipe_req_if.ready = ~stall;
endmodule