Finish splitting out functions.

[fpgaboy.git] / insn_jr-jrcc.v

diff --git a/insn_jr-jrcc.v b/insn_jr-jrcc.v
new file mode 100644 (file)
index 0000000..7a869b3
--- /dev/null
+++ b/insn_jr-jrcc.v
@@ -0,0 +1,38 @@
+`ifdef EXECUTE
+       `INSN_JR_imm,`INSN_JRCC_imm: begin
+               case (cycle)
+               0:      begin
+                               `EXEC_INC_PC;
+                               `EXEC_NEXTADDR_PCINC;
+                               rd <= 1;
+                       end
+               1: begin
+                               `EXEC_INC_PC;
+                               if (opcode[5]) begin    // i.e., JP cc,nn
+                                       /* We need to check the condition code to bail out. */
+                                       case (opcode[4:3])
+                                       `INSN_cc_NZ:    if (registers[`REG_F][7]) begin `EXEC_NEWCYCLE; end
+                                       `INSN_cc_Z:             if (~registers[`REG_F][7]) begin `EXEC_NEWCYCLE; end
+                                       `INSN_cc_NC:    if (registers[`REG_F][4]) begin `EXEC_NEWCYCLE; end
+                                       `INSN_cc_C:             if (~registers[`REG_F][4]) begin `EXEC_NEWCYCLE; end
+                                       endcase
+                               end
+                       end
+               2:      begin
+                               `EXEC_NEWCYCLE;
+                       end
+               endcase
+       end
+`endif
+
+`ifdef WRITEBACK
+       `INSN_JR_imm,`INSN_JRCC_imm: begin
+               case (cycle)
+               0:      begin /* type F */ end
+               1:      tmp <= rdata;
+               2:      {registers[`REG_PCH],registers[`REG_PCL]} <=
+                               {registers[`REG_PCH],registers[`REG_PCL]} +
+                               {tmp[7]?8'hFF:8'h00,tmp};
+               endcase
+       end
+`endif