Decode: Fix stupid bug in which stalls did not stall the decoder.
[firearm.git] / Execute.v
index 7c7f357..38a192f 100644 (file)
--- a/Execute.v
+++ b/Execute.v
@@ -21,7 +21,12 @@ module Execute(
        output reg [31:0] outspsr = 0,
        output reg write_reg = 1'bx,
        output reg [3:0] write_num = 4'bxxxx,
-       output reg [31:0] write_data = 32'hxxxxxxxx
+       output reg [31:0] write_data = 32'hxxxxxxxx,
+       output reg [31:0] jmppc,
+       output reg jmp,
+       output reg [31:0] outpc,
+       output reg [31:0] outinsn,
+       output reg [31:0] outop0, outop1, outop2
        );
        
        reg mult_start;
@@ -39,8 +44,9 @@ module Execute(
        reg [31:0] next_outcpsr, next_outspsr;
        reg next_write_reg;
        reg [3:0] next_write_num;
+
        reg [31:0] next_write_data;
-       
+
        Multiplier multiplier(
                .clk(clk), .Nrst(Nrst),
                .start(mult_start), .acc0(mult_acc0), .in0(mult_in0),
@@ -62,6 +68,11 @@ 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
 
@@ -72,23 +83,26 @@ module Execute(
        always @(*)
        begin
                outstall = stall;
-               next_outbubble = inbubble;
+               next_outbubble = inbubble | flush;
                next_outcpsr = cpsr;
                next_outspsr = spsr;
                next_write_reg = 0;
                next_write_num = 4'hx;
                next_write_data = 32'hxxxxxxxx;
-       
+
                mult_start = 0;
                mult_acc0 = 32'hxxxxxxxx;
                mult_in0 = 32'hxxxxxxxx;
                mult_in1 = 32'hxxxxxxxx;
-       
+
                alu_in0 = 32'hxxxxxxxx;
                alu_in1 = 32'hxxxxxxxx;
                alu_op = 4'hx;  /* hax! */
                alu_setflags = 1'bx;
-               
+
+               jmp = 1'b0;
+               jmppc = 32'h00000000;
+
                casez (insn)
                `DECODE_ALU_MULT:       /* Multiply -- must come before ALU, because it pattern matches a specific case of ALU */
                begin
@@ -153,8 +167,20 @@ module Execute(
                end
                `DECODE_LDRSTR_UNDEFINED,       /* Undefined. I hate ARM */
                `DECODE_LDRSTR,         /* Single data transfer */
-               `DECODE_LDMSTM,         /* Block data transfer */
-               `DECODE_BRANCH,         /* Branch */
+               `DECODE_LDMSTM:         /* Block data transfer */
+               begin end
+               `DECODE_BRANCH:
+               begin
+                       if(!inbubble) 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;
+                               end
+                               jmp = 1'b1;
+                       end
+               end                     /* Branch */
                `DECODE_LDCSTC,         /* Coprocessor data transfer */
                `DECODE_CDP,            /* Coprocessor data op */
                `DECODE_MRCMCR,         /* Coprocessor register transfer */
@@ -218,8 +244,8 @@ module ALU(
        output reg [31:0] cpsr_out,
        output reg setres
 );
-       wire [31:0] res;
-       wire flag_n, flag_z, flag_c, flag_v, setres;
+       reg [31:0] res;
+       reg flag_n, flag_z, flag_c, flag_v;
        wire [32:0] sum, diff, rdiff;
        wire sum_v, diff_v, rdiff_v;
 
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