X-Git-Url: http://git.joshuawise.com/fpgaboy.git/blobdiff_plain/b85870e0cf3c61677a430559c9621a665a8bab6d..634ce02ca41547deda6e98f0e16a81f849bb130c:/GBZ80Core.v?ds=sidebyside diff --git a/GBZ80Core.v b/GBZ80Core.v index e5a7d35..fa9ed0b 100644 --- a/GBZ80Core.v +++ b/GBZ80Core.v @@ -26,6 +26,8 @@ `define INSN_LD_HL_reg 8'b01110xxx `define INSN_LD_reg_HL 8'b01xxx110 `define INSN_LD_reg_reg 8'b01xxxxxx +`define INSN_LD_reg_imm16 8'b00xx0001 +`define INSN_LD_SP_HL 8'b11111001 `define INSN_reg_A 3'b111 `define INSN_reg_B 3'b000 `define INSN_reg_C 3'b001 @@ -34,7 +36,10 @@ `define INSN_reg_H 3'b100 `define INSN_reg_L 3'b101 `define INSN_reg_dHL 3'b110 - +`define INSN_reg16_BC 2'b00 +`define INSN_reg16_DE 2'b01 +`define INSN_reg16_HL 2'b10 +`define INSN_reg16_SP 2'b11 module GBZ80Core( input clk, output reg [15:0] busaddress, /* BUS_* is latched on STATE_FETCH. */ @@ -130,13 +135,42 @@ module GBZ80Core( endcase end `INSN_HALT: begin - /* XXX UNIMP */ + `EXEC_NEWCYCLE; + /* XXX Interrupts needed for HALT. */ end `INSN_LD_HL_reg: begin - /* XXX UNIMP */ + case (cycle) + 0: begin + case (opcode[2:0]) + `INSN_reg_A: begin wdata <= registers[`REG_A]; end + `INSN_reg_B: begin wdata <= registers[`REG_B]; end + `INSN_reg_C: begin wdata <= registers[`REG_C]; end + `INSN_reg_D: begin wdata <= registers[`REG_D]; end + `INSN_reg_E: begin wdata <= registers[`REG_E]; end + `INSN_reg_H: begin wdata <= registers[`REG_H]; end + `INSN_reg_L: begin wdata <= registers[`REG_L]; end + endcase + address <= {registers[`REG_H], registers[`REG_L]}; + wr <= 1; rd <= 0; + end + 1: begin + `EXEC_INC_PC; + `EXEC_NEWCYCLE; + end + endcase end `INSN_LD_reg_HL: begin - /* XXX UNIMP */ + case(cycle) + 0: begin + address <= {registers[`REG_H], registers[`REG_L]}; + wr <= 0; rd <= 1; + end + 1: begin + tmp <= rdata; + `EXEC_INC_PC; + `EXEC_NEWCYCLE; + end + endcase end `INSN_LD_reg_reg: begin `EXEC_INC_PC; @@ -151,46 +185,129 @@ module GBZ80Core( `INSN_reg_L: begin tmp <= registers[`REG_L]; end endcase end + `INSN_LD_reg_imm16: begin + `EXEC_INC_PC; + case (cycle) + 0: begin + `EXEC_NEXTADDR_PCINC; + rd <= 1; + end + 1: begin + `EXEC_NEXTADDR_PCINC; + rd <= 1; + end + 2: begin `EXEC_NEWCYCLE; end + endcase + end + `INSN_LD_SP_HL: begin + case (cycle) + 0: begin + rd <= 0; + address <= 16'bxxxxxxxxxxxxxxxx; + tmp <= registers[`REG_H]; + end + 1: begin + `EXEC_NEWCYCLE; + `EXEC_INC_PC; + tmp <= registers[`REG_L]; + end + endcase + end + default: + $stop; endcase state <= `STATE_WRITEBACK; end `STATE_WRITEBACK: begin casex (opcode) - `INSN_LD_reg_imm8: - case (cycle) - 0: cycle <= 1; - 1: case (opcode[5:3]) - `INSN_reg_A: begin registers[`REG_A] <= rdata; cycle <= 0; end - `INSN_reg_B: begin registers[`REG_B] <= rdata; cycle <= 0; end - `INSN_reg_C: begin registers[`REG_C] <= rdata; cycle <= 0; end - `INSN_reg_D: begin registers[`REG_D] <= rdata; cycle <= 0; end - `INSN_reg_E: begin registers[`REG_E] <= rdata; cycle <= 0; end - `INSN_reg_H: begin registers[`REG_H] <= rdata; cycle <= 0; end - `INSN_reg_L: begin registers[`REG_L] <= rdata; cycle <= 0; end - `INSN_reg_dHL: cycle <= 2; - endcase - 2: cycle <= 0; - endcase - `INSN_HALT: begin - /* XXX UNIMP */ - end - `INSN_LD_HL_reg: begin - /* XXX UNIMP */ - end - `INSN_LD_reg_HL: begin - /* XXX UNIMP */ - end - `INSN_LD_reg_reg: begin - case (opcode[5:3]) - `INSN_reg_A: begin registers[`REG_A] <= tmp; end - `INSN_reg_B: begin registers[`REG_B] <= tmp; end - `INSN_reg_C: begin registers[`REG_C] <= tmp; end - `INSN_reg_D: begin registers[`REG_D] <= tmp; end - `INSN_reg_E: begin registers[`REG_E] <= tmp; end - `INSN_reg_H: begin registers[`REG_H] <= tmp; end - `INSN_reg_L: begin registers[`REG_L] <= tmp; end + `INSN_LD_reg_imm8: + case (cycle) + 0: cycle <= 1; + 1: case (opcode[5:3]) + `INSN_reg_A: begin registers[`REG_A] <= rdata; cycle <= 0; end + `INSN_reg_B: begin registers[`REG_B] <= rdata; cycle <= 0; end + `INSN_reg_C: begin registers[`REG_C] <= rdata; cycle <= 0; end + `INSN_reg_D: begin registers[`REG_D] <= rdata; cycle <= 0; end + `INSN_reg_E: begin registers[`REG_E] <= rdata; cycle <= 0; end + `INSN_reg_H: begin registers[`REG_H] <= rdata; cycle <= 0; end + `INSN_reg_L: begin registers[`REG_L] <= rdata; cycle <= 0; end + `INSN_reg_dHL: cycle <= 2; endcase - end + 2: cycle <= 0; + endcase + `INSN_HALT: begin + /* Nothing needs happen here. */ + /* XXX Interrupts needed for HALT. */ + end + `INSN_LD_HL_reg: begin + case (cycle) + 0: cycle <= 1; + 1: cycle <= 0; + endcase + end + `INSN_LD_reg_HL: begin + case (cycle) + 0: cycle <= 1; + 1: begin + case (opcode[5:3]) + `INSN_reg_A: begin registers[`REG_A] <= tmp; end + `INSN_reg_B: begin registers[`REG_B] <= tmp; end + `INSN_reg_C: begin registers[`REG_C] <= tmp; end + `INSN_reg_D: begin registers[`REG_D] <= tmp; end + `INSN_reg_E: begin registers[`REG_E] <= tmp; end + `INSN_reg_H: begin registers[`REG_H] <= tmp; end + `INSN_reg_L: begin registers[`REG_L] <= tmp; end + endcase + cycle <= 0; + end + endcase + end + `INSN_LD_reg_reg: begin + case (opcode[5:3]) + `INSN_reg_A: begin registers[`REG_A] <= tmp; end + `INSN_reg_B: begin registers[`REG_B] <= tmp; end + `INSN_reg_C: begin registers[`REG_C] <= tmp; end + `INSN_reg_D: begin registers[`REG_D] <= tmp; end + `INSN_reg_E: begin registers[`REG_E] <= tmp; end + `INSN_reg_H: begin registers[`REG_H] <= tmp; end + `INSN_reg_L: begin registers[`REG_L] <= tmp; end + endcase + end + `INSN_LD_reg_imm16: begin + case (cycle) + 0: cycle <= 1; + 1: begin + case (opcode[5:4]) + `INSN_reg16_BC: registers[`REG_C] <= rdata; + `INSN_reg16_DE: registers[`REG_E] <= rdata; + `INSN_reg16_HL: registers[`REG_L] <= rdata; + `INSN_reg16_SP: registers[`REG_SPL] <= rdata; + endcase + cycle <= 2; + end + 2: begin + case (opcode[5:4]) + `INSN_reg16_BC: registers[`REG_B] <= rdata; + `INSN_reg16_DE: registers[`REG_D] <= rdata; + `INSN_reg16_HL: registers[`REG_H] <= rdata; + `INSN_reg16_SP: registers[`REG_SPH] <= rdata; + endcase + cycle <= 0; + end + endcase + end + `INSN_LD_SP_HL: begin + case (cycle) + 0: begin + cycle <= 1; + registers[`REG_SPH] <= tmp; + end + 1: begin + cycle <= 0; + registers[`REG_SPL] <= tmp; + end + endcase + end endcase state <= `STATE_FETCH; end