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[fpgaboy.git] / core / insn_alu_ext.v

diff --git a/core/insn_alu_ext.v b/core/insn_alu_ext.v
index 1b7825bda50dcc08df68c9f0e103e8dc13835a78..5ae8fe8c96fc3b3adc2612311911c56045b7f666 100644 (file)
--- a/core/insn_alu_ext.v
+++ b/core/insn_alu_ext.v
@@ -1,3 +1,66 @@
+`define INSN_ALU_EXT           9'b100xxxxxx
+
+`ifdef LOCALWIRES
+       wire [7:0] rlc,rrc,rl,rr,sla,sra,swap,srl;
+       wire [3:0] rlcf,rrcf,rlf,rrf,slaf,sraf,swapf,srlf;
+       wire [7:0] alu_res;
+       wire [3:0] f_res;
+
+       assign rlc   = {tmp[6:0],tmp[7]};
+       assign rlcf  = {(tmp == 0 ? 1'b1 : 1'b0)
+                       ,2'b0,
+                       tmp[7]};
+
+       assign rrc   = {tmp[0],tmp[7:1]};
+       assign rrcf  = {(tmp == 0 ? 1'b1 : 1'b0),
+                       2'b0,
+                       tmp[0]};
+
+       assign rl    = {tmp[6:0],`_F[4]};
+       assign rlf   = {({tmp[6:0],`_F[4]} == 0 ? 1'b1 : 1'b0),
+                       2'b0,
+                       tmp[7]};
+
+       assign rr    = {`_F[4],tmp[7:1]};
+       assign rrf   = {({`_F[4],tmp[7:1]} == 0 ? 1'b1 : 1'b0),
+                       2'b0,
+                       tmp[0]};
+
+       assign sla   = {tmp[6:0],1'b0};
+       assign slaf  = {(tmp[6:0] == 0 ? 1'b1 : 1'b0),
+                       2'b0,
+                       tmp[7]};
+
+       assign sra   = {tmp[7],tmp[7:1]};
+//     assign sraf  = {(tmp[7:1] == 0 ? 1'b1 : 1'b0),2'b0,tmp[0]};   now in assign srlf =
+
+       assign swap  = {tmp[3:0],tmp[7:4]};
+       assign swapf = {(tmp == 1'b0 ? 1'b1 : 1'b0),
+                       3'b0};
+
+       assign srl   = {1'b0,tmp[7:1]};
+       assign srlf  = {(tmp[7:1] == 0 ? 1'b1 : 1'b0),
+                       2'b0,
+                       tmp[0]};
+       assign sraf  = srlf;
+
+       /*  Y U Q  */
+       assign {alu_res,f_res} =
+               opcode[5] ? (
+                       opcode[4] ? (
+                               opcode[3] ? {srl,srlf} : {swap,swapf}
+                       ) : (
+                               opcode[3] ? {sra,sraf} : {sla,slaf}
+                       )
+               ) : (
+                       opcode[4] ? (
+                               opcode[3] ? {rr,rrf} : {rl,rlf}
+                       ) : (
+                               opcode[3] ? {rrc,rrcf} : {rlc,rlcf}
+                       )
+               );
+`endif
+
 `ifdef EXECUTE
        `INSN_ALU_EXT: begin
                if ((opcode[2:0] == `INSN_reg_dHL) && (cycle == 0))
@@ -24,6 +87,7 @@
                        if(cycle == 0) begin end
                        else if(cycle == 1) begin
                                `EXEC_WRITE(`_HL, alu_res)
+                               `_F <= {f_res,`_F[3:0]};
                        end else begin
                                `EXEC_NEWCYCLE
                        end