diff options
-rw-r--r-- | alu_stage.v | 21 | ||||
-rw-r--r-- | nqcpu.v | 17 |
2 files changed, 34 insertions, 4 deletions
diff --git a/alu_stage.v b/alu_stage.v index 3761f25..7bdbfe8 100644 --- a/alu_stage.v +++ b/alu_stage.v @@ -20,6 +20,10 @@ module alu_stage ( input [15:0] memData_in, // read in from memory output reg [15:0] memData_out, // to write out to memory + // setting PC + output setPC, + output [15:0] setPCValue, + output reg [32:0] control_signals_out, output reg [15:0] imm_out, output reg [15:0] pc_out, @@ -90,14 +94,29 @@ module alu_stage ( .carry(aluCarry) ); + wire setRegZCond, setRegCCond, setSomeReg; + assign setRegZCond = setRegCond_in[4] | (setRegCond_in[3] == statusReg[1]); + assign setRegCCond = setRegCond_in[1] | (setRegCond_in[0] == statusReg[0]); + assign setSomeReg = + en & + setRegCond_in[5] & + ( + setRegCond_in[2] ? + (setRegZCond & setRegCCond) : + (setRegZCond | setRegCCond) + ); + assign rf_regA = aluReg1_in; assign rf_regB = aluReg2_in; - assign rf_we = en & (regSetH_in | regSetL_in); + assign rf_we = setSomeReg & !aluDest_in; assign rf_hb = regSetH_in; assign rf_lb = regSetL_in; assign rf_dataIn = aluResult; assign rf_regDest = regDest_in; + assign setPC = setSomeReg & aluDest_in; + assign setPCValue = aluResult; + always @(posedge clk) begin if(en) begin control_signals_out <= control_signals_in; @@ -31,6 +31,9 @@ module nqcpu ( output [15:0] dbg_r7, output [9:0] dbg_state, + output dbg_setPC, + output [15:0] dbg_setPCValue, + output [1:0] dbg_statusreg ); @@ -40,7 +43,8 @@ module nqcpu ( pc = 16'h0; end - wire fetch_en, decode_en, alu_en, incr_pc; + wire fetch_en, decode_en, alu_en, incr_pc, setPC; + wire [15:0] setPCValue; wire fetch_ready; wire [15:0] fetched_instr; @@ -58,6 +62,9 @@ module nqcpu ( if(incr_pc) begin pc <= pc + 16'h2; end + else if (setPC & alu_en) begin + pc <= setPCValue; + end end wire [32:0] ctrl_from_decoder; @@ -130,6 +137,9 @@ module nqcpu ( .memData_in(16'hDEAD), // read in from memory //.memData_out(??), // to write out to memory + .setPC(setPC), + .setPCValue(setPCValue), + .control_signals_out(ctrl_from_alu), .imm_out(imm_from_alu), .pc_out(pc_from_alu), @@ -174,6 +184,7 @@ module nqcpu ( .setRegCond(debugSetRegCond) ); - assign debugPC = pc_from_alu; - + assign debugPC = pc; + assign dbg_setPC = setPC; + assign dbg_setPCValue = setPCValue; endmodule |