X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/b057a5d6e6db6db06ae33703ca72cd235eec91d6..62316b58608c6d4333cc301b9906e13d143ba36e:/core/insn_alu_ext.v diff --git a/core/insn_alu_ext.v b/core/insn_alu_ext.v index 1b7825b..5ae8fe8 100644 --- 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