github-mirrors/serv
1
0
Fork 0
mirror of https://github.com/olofk/serv.git synced 2025-04-22 12:57:09 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

Use two write ports for RF/CSR RAM

Browse source
This commit is contained in:
Olof Kindgren 2019-07-28 13:30:39 +02:00
parent a0ba84096a
commit 8cd9742b53
1 changed files with 27 additions and 19 deletions
Download patch file Download diff file Expand all files Collapse all files

46
rtl/serv_mpram.v
View file

@ -33,49 +33,57 @@ module serv_mpram
reg [4:0] wdata0;
reg [5:0] wdata1;
reg [6:0] wdata2;
reg [7:0] wdata3;
wire [3:0] wdata;
wire wen;
reg [3:0] wen_r;
reg [1:0] wen_r;
reg [3:0] wcnt_lo;
reg [2:0] wcnt_hi;
reg wgo_r;
assign wdata = wcnt_lo[0] ? wdata0[3:0] :
wcnt_lo[1] ? wdata1[3:0] :
wcnt_lo[2] ? wdata2[3:0] :
/*wcnt_lo[3] ?*/ wdata3[3:0];
assign wen = !wgo_r & |(wen_r & wcnt_lo);
assign wdata = wcnt_lo[0] ? wdata0[3:0] : wdata1[3:0];
assign wen = !wgo_r & |(wen_r & wcnt_lo[1:0]);
reg [4:0] rd_waddr;
//port 0 rd mtval
//port 1 csr mepc
//mepc 100010
//mtval 100011
//csr 1000xx
//rd 0xxxxx
assign waddr[8] = !wcnt_lo[3];
assign waddr[7:5] = wcnt_lo[3] ? rd_waddr[4:2] : 3'b000;
assign waddr[4:3] = wcnt_lo[3] ? rd_waddr[1:0] :
wcnt_lo[2] ? i_csr_addr :
wcnt_lo[1] ? CSR_MTVAL : CSR_MEPC;
wire [5:0] waddr0 = trap_3r ? {4'b1000,CSR_MTVAL} : {1'b0,rd_waddr};
wire [5:0] waddr1 = trap_3r ? {4'b1000,CSR_MEPC} : {4'b1000,i_csr_addr};
assign waddr[8:3] = wcnt_lo[0] ? waddr0 : waddr1;
// assign waddr[8] = wcnt_lo[1] | i_trap;
// assign waddr[7:5] = (wcnt_lo[1] | i_trap) ? 3'b000 : rd_waddr[4:2];
// assign waddr[4:3] = wcnt_lo[0] ? (i_trap ? CSR_MTVAL : rd_waddr[1:0]) :
// (i_trap ? CSR_MEPC : i_csr_addr);
assign waddr[2:0] = wcnt_hi;
wire wgo = !(|wcnt_lo) & |({i_rd_wen,i_csr_en,i_trap, i_trap});
wire wgo = !(|wcnt_lo) & (i_rd_wen | i_csr_en | i_trap);
reg trap_r;
reg trap_2r;
reg trap_3r;
always @(posedge i_clk) begin
trap_r <= i_trap;
trap_2r <= trap_r;
trap_3r <= trap_2r;
if (wgo) begin
wgo_r <= 1'b1;
wen_r <= {i_rd_wen,i_csr_en,i_trap,i_trap};
wen_r <= {i_csr_en|i_trap,i_rd_wen|i_trap};
rd_waddr <= i_rd_waddr;
end
wdata0 <= {i_mepc,wdata0[4:1]};
wdata1 <= {i_mtval,wdata1[5:1]};
wdata2 <= {i_csr,wdata2[6:1]};
wdata3 <= {i_rd,wdata3[7:1]};
wdata0 <= {i_trap ? i_mtval : i_rd ,wdata0[4:1]};
wdata1 <= {i_trap ? i_mepc : i_csr,wdata1[5:1]};
wcnt_lo <= {wcnt_lo[2:0],wcnt_lo[3] | wgo};
if (wcnt_lo[3]) begin
wcnt_hi <= wcnt_hi + 1;