core/insn_ldm16_a.v

   1 `define INSN_LD16M_A            9'b0111x1010    // 1111 for ld A, x; 1110 for ld x, A; bit 1 specifies 16m8 or 8m8
   2
   3 // If opcode[4], then ld A, x, else ld x, A
   4 // If opcode[1], then ld 16m8, else ld 8m8
   5
   6 `ifdef EXECUTE
   7         `INSN_LD16M_A: begin
   8                 case (cycle)
   9                 0:      begin
  10                                 `EXEC_INC_PC
  11                                 `EXEC_READ(`_PC + 16'h0001)
  12                         end
  13                 1:      begin
  14                                 `EXEC_INC_PC                    // we only hit here if 16m8
  15                                 `EXEC_READ(`_PC + 16'h0001)
  16                         end
  17                 2:      if (opcode[4])  // LD A,x
  18                                 `EXEC_READ(({rdata, tmp}))
  19                         else
  20                                 `EXEC_WRITE(({rdata, tmp}), `_A)
  21                 3:      begin
  22                                 `EXEC_NEWCYCLE
  23                                 `EXEC_INC_PC
  24                         end
  25                 endcase
  26         end
  27 `endif
  28
  29 `ifdef WRITEBACK
  30         `INSN_LD16M_A: begin
  31                 case (cycle)
  32                 0:      begin end
  33                 1:      tmp <= rdata;
  34                 2:      begin end
  35                 3:      if (opcode[4]) `_A <= rdata;
  36                 endcase
  37         end
  38 `endif
  39