X-Git-Url: http://git.joshuawise.com/firearm.git/blobdiff_plain/7947b9c731a2c981f1a32d2f8f47ab42464e7b17..81a01a2b3225a62f9f0af74e5b2480c51ddbd1fe:/Execute.v diff --git a/Execute.v b/Execute.v index 8a7d8f6..ac828a5 100644 --- a/Execute.v +++ b/Execute.v @@ -23,7 +23,10 @@ module Execute( output reg [3:0] write_num = 4'bxxxx, output reg [31:0] write_data = 32'hxxxxxxxx, output reg [31:0] jmppc, - output reg jmp + output reg jmp, + output reg [31:0] outpc, + output reg [31:0] outinsn, + output reg [31:0] outop0, outop1, outop2 ); reg mult_start; @@ -54,7 +57,7 @@ module Execute( .in0(alu_in0), .in1(alu_in1), .cpsr(cpsr), .op(alu_op), .setflags(alu_setflags), .shifter_carry(carry), .result(alu_result), .cpsr_out(alu_outcpsr), .setres(alu_setres)); - + always @(posedge clk) begin if (!stall) @@ -65,8 +68,20 @@ module Execute( write_reg <= next_write_reg; write_num <= next_write_num; write_data <= next_write_data; + outpc <= pc; + outinsn <= insn; + outop0 <= op0; + outop1 <= op1; + outop2 <= op2; end end + + reg delayedflush = 0; + always @(posedge clk) + if (flush && outstall /* halp! I can't do it now, maybe later? */) + delayedflush <= 1; + else if (!outstall /* anything has been handled this time around */) + delayedflush <= 0; reg prevstall = 0; always @(posedge clk) @@ -75,7 +90,7 @@ module Execute( always @(*) begin outstall = stall; - next_outbubble = inbubble | flush; + next_outbubble = inbubble | flush | delayedflush; next_outcpsr = cpsr; next_outspsr = spsr; next_write_reg = 0; @@ -93,7 +108,7 @@ module Execute( alu_setflags = 1'bx; jmp = 1'b0; - jmppc = 32'hxxxxxxxx; + jmppc = 32'h00000000; casez (insn) `DECODE_ALU_MULT: /* Multiply -- must come before ALU, because it pattern matches a specific case of ALU */ @@ -106,8 +121,8 @@ module Execute( mult_in1 = op2 /* Rs */; $display("New MUL instruction"); end - outstall = stall | ((!prevstall | !mult_done) && !inbubble); - next_outbubble = inbubble | !mult_done | !prevstall; + outstall = outstall | ((!prevstall | !mult_done) && !inbubble); + next_outbubble = next_outbubble | !mult_done | !prevstall; next_outcpsr = insn[20] /* S */ ? {mult_result[31] /* N */, mult_result == 0 /* Z */, 1'b0 /* C */, cpsr[28] /* V */, cpsr[27:0]} : cpsr; next_write_reg = 1; next_write_num = insn[19:16] /* Rd -- why the fuck isn't this the same place as ALU */; @@ -163,12 +178,12 @@ module Execute( begin end `DECODE_BRANCH: begin - if(!inbubble) begin + if(!inbubble && !flush && !delayedflush) begin jmppc = pc + op0 + 32'h8; if(insn[24]) begin next_write_reg = 1; next_write_num = 4'hE; /* link register */ - next_write_data = pc - 32'h4; + next_write_data = pc + 32'h4; end jmp = 1'b1; end