input clk,
input Nrst, /* XXX not used yet */
- input stall,
- input flush,
+ input stall_2a,
+ input flush_2a,
- input inbubble,
- input [31:0] pc,
- input [31:0] insn,
- input [31:0] cpsr,
- input [31:0] spsr,
- input [31:0] op0,
- input [31:0] op1,
- input [31:0] op2,
- input carry,
+ input bubble_2a,
+ input [31:0] pc_2a,
+ input [31:0] insn_2a,
+ input [31:0] cpsr_2a,
+ input [31:0] spsr_2a,
+ input [31:0] op0_2a,
+ input [31:0] op1_2a,
+ input [31:0] op2_2a,
+ input carry_2a,
- output reg outstall = 0,
- output reg outbubble = 1,
- output reg [31:0] outcpsr = 0,
- output reg [31:0] outspsr = 0,
- output reg outcpsrup = 0,
- output reg write_reg = 1'bx,
- output reg [3:0] write_num = 4'bxxxx,
- output reg [31:0] write_data = 32'hxxxxxxxx,
- output reg [31:0] jmppc,
- output reg jmp,
- output reg [31:0] outpc,
- output reg [31:0] outinsn,
- output reg [31:0] outop0, outop1, outop2
+ output reg outstall_2a = 0,
+ output reg bubble_3a = 1,
+ output reg [31:0] cpsr_3a = 0,
+ output reg [31:0] spsr_3a = 0,
+ output reg cpsrup_3a = 0,
+ output reg write_reg_3a = 1'bx,
+ output reg [3:0] write_num_3a = 4'bxxxx,
+ output reg [31:0] write_data_3a = 32'hxxxxxxxx,
+ output reg [31:0] jmppc_2a,
+ output reg jmp_2a,
+ output reg [31:0] pc_3a,
+ output reg [31:0] insn_3a,
+ output reg [31:0] op0_3a, op1_3a, op2_3a
);
reg mult_start;
wire mult_done;
wire [31:0] mult_result;
- reg [31:0] alu_in0, alu_in1;
- reg [3:0] alu_op;
- reg alu_setflags;
- wire [31:0] alu_result, alu_outcpsr;
- wire alu_setres;
+ reg [31:0] alu_in0_2a, alu_in1_2a;
+ reg [3:0] alu_op_2a;
+ reg alu_setflags_2a;
+ wire [31:0] alu_result_2a, alu_outcpsr_2a;
+ wire alu_setres_2a;
- reg next_outbubble;
- reg [31:0] next_outcpsr, next_outspsr;
- reg next_outcpsrup;
- reg next_write_reg;
- reg [3:0] next_write_num;
-
- reg [31:0] next_write_data;
+ reg next_bubble_3a;
+ reg [31:0] next_cpsr_3a, next_spsr_3a;
+ reg next_cpsrup_3a;
+
+ reg next_write_reg_3a;
+ reg [3:0] next_write_num_3a;
+ reg [31:0] next_write_data_3a;
Multiplier multiplier(
.clk(clk), .Nrst(Nrst),
ALU alu(
.clk(clk), .Nrst(Nrst),
- .in0(alu_in0), .in1(alu_in1), .cpsr(cpsr), .op(alu_op),
- .setflags(alu_setflags), .shifter_carry(carry),
- .result(alu_result), .cpsr_out(alu_outcpsr), .setres(alu_setres));
+ .in0(alu_in0_2a), .in1(alu_in1_2a), .cpsr(cpsr_2a), .op(alu_op_2a),
+ .setflags(alu_setflags_2a), .shifter_carry(carry_2a),
+ .result(alu_result_2a), .cpsr_out(alu_outcpsr_2a), .setres(alu_setres_2a));
always @(posedge clk)
begin
- if (!stall)
+ if (!stall_2a)
begin
- outbubble <= next_outbubble;
- outcpsr <= next_outcpsr;
- outspsr <= next_outspsr;
- outcpsrup <= next_outcpsrup;
- write_reg <= next_write_reg;
- write_num <= next_write_num;
- write_data <= next_write_data;
- outpc <= pc;
- outinsn <= insn;
- outop0 <= op0;
- outop1 <= op1;
- outop2 <= op2;
+ bubble_3a <= next_bubble_3a;
+ cpsr_3a <= next_cpsr_3a;
+ spsr_3a <= next_spsr_3a;
+ cpsrup_3a <= next_cpsrup_3a;
+ write_reg_3a <= next_write_reg_3a;
+ write_num_3a <= next_write_num_3a;
+ write_data_3a <= next_write_data_3a;
+ pc_3a <= pc_2a;
+ insn_3a <= insn_2a;
+ op0_3a <= op0_2a;
+ op1_3a <= op1_2a;
+ op2_3a <= op2_2a;
end
end
- reg delayedflush = 0;
+ reg delayedflush_2a = 0;
always @(posedge clk)
- if (flush && outstall /* halp! I can't do it now, maybe later? */)
- delayedflush <= 1;
- else if (!outstall /* anything has been handled this time around */)
- delayedflush <= 0;
+ if (flush_2a && outstall_2a /* halp! I can't do it now, maybe later? */)
+ delayedflush_2a <= 1;
+ else if (!outstall_2a /* anything has been handled this time around */)
+ delayedflush_2a <= 0;
- reg prevstall = 0;
+ reg outstall_3a = 0;
always @(posedge clk)
- prevstall <= outstall;
+ outstall_3a <= outstall_2a;
always @(*)
begin
- outstall = stall;
+ outstall_2a = stall_2a;
- casez (insn)
+ casez (insn_2a)
`DECODE_ALU_MULT: /* Multiply -- must come before ALU, because it pattern matches a specific case of ALU */
- outstall = outstall | ((!prevstall | !mult_done) && !inbubble);
+ outstall_2a = outstall_2a | ((!outstall_3a | !mult_done) && !bubble_2a);
endcase
end
/* ALU inputs */
always @(*)
begin
- alu_in0 = op0;
- alu_in1 = op1;
- alu_op = insn[24:21];
- alu_setflags = insn[20] /* S */;
+ alu_in0_2a = op0_2a;
+ alu_in1_2a = op1_2a;
+ alu_op_2a = insn_2a[24:21];
+ alu_setflags_2a = insn_2a[20] /* S */;
end
/* Register outputs */
always @(*)
begin
- next_outcpsr = cpsr;
- next_outspsr = spsr;
- next_outcpsrup = 0;
- next_write_reg = 0;
- next_write_num = 4'hx;
- next_write_data = 32'hxxxxxxxx;
+ next_cpsr_3a = cpsr_2a;
+ next_spsr_3a = spsr_2a;
+ next_cpsrup_3a = 0;
+ next_write_reg_3a = 0;
+ next_write_num_3a = 4'hx;
+ next_write_data_3a = 32'hxxxxxxxx;
- casez(insn)
+ casez(insn_2a)
`DECODE_ALU_MULT: /* Multiply -- must come before ALU, because it pattern matches a specific case of ALU */
begin
- next_outcpsr = insn[20] /* S */ ? {mult_result[31] /* N */, mult_result == 0 /* Z */, 1'b0 /* C */, cpsr[28] /* V */, cpsr[27:0]} : cpsr;
- next_outcpsrup = insn[20] /* S */;
- next_write_reg = 1;
- next_write_num = insn[19:16] /* Rd -- why the fuck isn't this the same place as ALU */;
- next_write_data = mult_result;
+ next_cpsr_3a = insn_2a[20] /* S */ ? {mult_result[31] /* N */, mult_result == 0 /* Z */, 1'b0 /* C */, cpsr_2a[28] /* V */, cpsr_2a[27:0]} : cpsr_2a;
+ next_cpsrup_3a = insn_2a[20] /* S */;
+ next_write_reg_3a = 1;
+ next_write_num_3a = insn_2a[19:16] /* Rd -- why the fuck isn't this the same place as ALU */;
+ next_write_data_3a = mult_result;
end
`DECODE_ALU_MRS: /* MRS (Transfer PSR to register) */
begin
- next_write_reg = 1;
- next_write_num = insn[15:12];
- if (insn[22] /* Ps */)
- next_write_data = spsr;
+ next_write_reg_3a = 1;
+ next_write_num_3a = insn_2a[15:12];
+ if (insn_2a[22] /* Ps */)
+ next_write_data_3a = spsr_2a;
else
- next_write_data = cpsr;
+ next_write_data_3a = cpsr_2a;
end
`DECODE_ALU_MSR, /* MSR (Transfer register to PSR) */
`DECODE_ALU_MSR_FLAGS: /* MSR (Transfer register or immediate to PSR, flag bits only) */
begin
- if ((cpsr[4:0] == `MODE_USR) || (insn[16] /* that random bit */ == 1'b0)) /* flags only */
+ if ((cpsr_2a[4:0] == `MODE_USR) || (insn_2a[16] /* that random bit */ == 1'b0)) /* flags only */
begin
- if (insn[22] /* Ps */)
- next_outspsr = {op0[31:29], spsr[28:0]};
+ if (insn_2a[22] /* Ps */)
+ next_spsr_3a = {op0_2a[31:29], spsr_2a[28:0]};
else
- next_outcpsr = {op0[31:29], cpsr[28:0]};
+ next_cpsr_3a = {op0_2a[31:29], cpsr_2a[28:0]};
end else begin
- if (insn[22] /* Ps */)
- next_outspsr = op0;
+ if (insn_2a[22] /* Ps */)
+ next_spsr_3a = op0_2a;
else
- next_outcpsr = op0;
+ next_cpsr_3a = op0_2a;
end
- next_outcpsrup = 1;
+ next_cpsrup_3a = 1;
end
`DECODE_ALU_SWP, /* Atomic swap */
`DECODE_ALU_BX, /* Branch */
begin end
`DECODE_ALU: /* ALU */
begin
- if (alu_setres) begin
- next_write_reg = 1;
- next_write_num = insn[15:12] /* Rd */;
- next_write_data = alu_result;
+ if (alu_setres_2a) begin
+ next_write_reg_3a = 1;
+ next_write_num_3a = insn_2a[15:12] /* Rd */;
+ next_write_data_3a = alu_result_2a;
end
- if (insn[20] /* S */) begin
- next_outcpsrup = 1;
- next_outcpsr = ((insn[15:12] == 4'b1111) && insn[20]) ? spsr : alu_outcpsr;
+ if (insn_2a[20] /* S */) begin
+ next_cpsrup_3a = 1;
+ next_cpsr_3a = ((insn_2a[15:12] == 4'b1111) && insn_2a[20]) ? spsr_2a : alu_outcpsr_2a;
end
end
`DECODE_LDRSTR_UNDEFINED, /* Undefined. I hate ARM */
begin end
`DECODE_BRANCH: /* Branch */
begin
- if(insn[24] /* L */) begin
- next_write_reg = 1;
- next_write_num = 4'hE; /* link register */
- next_write_data = pc + 32'h4;
+ if(insn_2a[24] /* L */) begin
+ next_write_reg_3a = 1;
+ next_write_num_3a = 4'hE; /* link register */
+ next_write_data_3a = pc_2a + 32'h4;
end
end
endcase
mult_in0 = 32'hxxxxxxxx;
mult_in1 = 32'hxxxxxxxx;
- casez(insn)
+ casez(insn_2a)
`DECODE_ALU_MULT:
begin
- if (!prevstall /* i.e., this is a new one */ && !inbubble /* i.e., this is a real one */)
+ if (!outstall_3a /* i.e., this is a new one */ && !bubble_2a /* i.e., this is a real one */)
begin
mult_start = 1;
- mult_acc0 = insn[21] /* A */ ? op0 /* Rn */ : 32'h0;
- mult_in0 = op1 /* Rm */;
- mult_in1 = op2 /* Rs */;
+ mult_acc0 = insn_2a[21] /* A */ ? op0_2a /* Rn */ : 32'h0;
+ mult_in0 = op1_2a /* Rm */;
+ mult_in1 = op2_2a /* Rs */;
$display("New MUL instruction");
end
end
/* Miscellaneous cleanup. */
always @(*)
begin
- next_outbubble = inbubble | flush | delayedflush;
+ next_bubble_3a = bubble_2a | flush_2a | delayedflush_2a;
- jmp = 1'b0;
- jmppc = 32'h00000000;
+ jmp_2a = 1'b0;
+ jmppc_2a = 32'h00000000;
- casez (insn)
+ casez (insn_2a)
`DECODE_ALU_MULT: /* Multiply -- must come before ALU, because it pattern matches a specific case of ALU */
- next_outbubble = next_outbubble | !mult_done | !prevstall;
+ next_bubble_3a = next_bubble_3a | !mult_done | !outstall_3a;
`DECODE_ALU_MRS, /* MRS (Transfer PSR to register) */
`DECODE_ALU_MSR, /* MSR (Transfer register to PSR) */
`DECODE_ALU_MSR_FLAGS, /* MSR (Transfer register or immediate to PSR, flag bits only) */
begin end
`DECODE_BRANCH:
begin
- if(!inbubble && !flush && !delayedflush && !outstall /* Let someone else take precedence. */) begin
- jmppc = pc + op0 + 32'h8;
- jmp = 1'b1;
+ if(!bubble_2a && !flush_2a && !delayedflush_2a && !outstall_2a /* Let someone else take precedence. */) begin
+ jmppc_2a = pc_2a + op0_2a + 32'h8;
+ jmp_2a = 1'b1;
end
end /* Branch */
`DECODE_LDCSTC, /* Coprocessor data transfer */
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