added branch support, maybe

[firearm.git] / Execute.v

diff --git a/Execute.v b/Execute.v
index 7c7f35738011455631b86f9413e028e221ccda53..cefc4ef00d2c0d23535f938e3c3e91494764e25b 100644 (file)
--- a/Execute.v
+++ b/Execute.v
@@ -21,7 +21,9 @@ 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
        );
        
        reg mult_start;
@@ -39,8 +41,9 @@ 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),
@@ -72,23 +75,26 @@ 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'hxxxxxxxx;
+
                casez (insn)
                `DECODE_ALU_MULT:       /* Multiply -- must come before ALU, because it pattern matches a specific case of ALU */
                begin
@@ -153,8 +159,18 @@ 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
+                       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                     /* Branch */
                `DECODE_LDCSTC,         /* Coprocessor data transfer */
                `DECODE_CDP,            /* Coprocessor data op */
                `DECODE_MRCMCR,         /* Coprocessor register transfer */