if (cp_busy) begin
outstall = 1;
end
+ if (!cp_ack) begin
+ /* XXX undefined instruction trap */
+ $display("WARNING: Possible CDP undefined instruction");
+ end
end
`DECODE_MRCMCR: if (!inbubble) begin
if (cp_busy) begin
outstall = 1;
end
+ if (!cp_ack) begin
+ $display("WARNING: Possible MRCMCR undefined instruction: cp_ack %d, cp_busy %d",cp_ack, cp_busy);
+ end
$display("MRCMCR: ack %d, busy %d", cp_ack, cp_busy);
end
default: begin end
endcase
end
-
+
+ /* Coprocessor input. */
+ always @(*)
+ begin
+ cp_req = 0;
+ cp_rnw = 1'bx;
+ cp_write = 32'hxxxxxxxx;
+ casez (insn)
+ `DECODE_CDP: if(!inbubble) begin
+ cp_req = 1;
+ end
+ `DECODE_MRCMCR: if(!inbubble) begin
+ cp_req = 1;
+ cp_rnw = insn[20] /* L */;
+ if (insn[20] == 0 /* store to coprocessor */)
+ cp_write = op0;
+ end
+ endcase
+ end
+
+ /* Register output logic. */
always @(*)
begin
- addr = prevaddr;
- raddr = 32'hxxxxxxxx;
- rd_req = 1'b0;
- wr_req = 1'b0;
- wr_data = 32'hxxxxxxxx;
- busaddr = 32'hxxxxxxxx;
- data_size = 3'bxxx;
- st_read = 4'hx;
- do_rd_data_latch = 0;
next_write_reg = write_reg;
next_write_num = write_num;
next_write_data = write_data;
- next_outbubble = inbubble;
- next_regs = regs;
- cp_req = 1'b0;
- cp_rnw = 1'bx;
- cp_write = 32'hxxxxxxxx;
- offset = prev_offset;
next_outcpsr = lsm_state == 4'b0010 ? outcpsr : cpsr;
next_outcpsrup = cpsrup;
- lsrh_rddata = 32'hxxxxxxxx;
- lsrh_rddata_s1 = 16'hxxxx;
- lsrh_rddata_s2 = 8'hxx;
- next_swp_oldval = swp_oldval;
- cur_reg = prev_reg;
-
- /* XXX shit not given about endianness */
+
+ casez(insn)
+ `DECODE_ALU_SWP: if (!inbubble) begin
+ next_write_reg = 1'bx;
+ next_write_num = 4'bxxxx;
+ next_write_data = 32'hxxxxxxxx;
+ case(swp_state)
+ `SWP_READING:
+ next_write_reg = 1'b0;
+ `SWP_WRITING: begin
+ next_write_reg = 1'b1;
+ next_write_num = insn[15:12];
+ next_write_data = insn[22] ? {24'b0, swp_oldval[7:0]} : swp_oldval;
+ end
+ default: begin end
+ endcase
+ end
+ `DECODE_ALU_MULT: begin end
+ `DECODE_ALU_HDATA_REG,
+ `DECODE_ALU_HDATA_IMM: if(!inbubble) begin
+ next_write_reg = 1'bx;
+ next_write_num = 4'bxxxx;
+ next_write_data = 32'hxxxxxxxx;
+ case(lsrh_state)
+ `LSRH_MEMIO: begin
+ next_write_num = insn[15:12];
+ next_write_data = lsrh_rddata;
+ if(insn[20]) begin
+ next_write_reg = 1'b1;
+ end
+ end
+ `LSRH_BASEWB: begin
+ next_write_reg = 1'b1;
+ next_write_num = insn[19:16];
+ next_write_data = addr;
+ end
+ `LSRH_WBFLUSH:
+ next_write_reg = 1'b0;
+ default: begin end
+ endcase
+ end
+ `DECODE_LDRSTR_UNDEFINED: begin end
+ `DECODE_LDRSTR: if(!inbubble) begin
+ next_write_reg = 1'bx;
+ next_write_num = 4'bxxxx;
+ next_write_data = 32'hxxxxxxxx;
+ case(lsr_state)
+ `LSR_MEMIO: begin
+ next_write_reg = insn[20] /* L */;
+ next_write_num = insn[15:12];
+ if(insn[20] /* L */) begin
+ next_write_data = insn[22] /* B */ ? {24'h0, align_rddata[7:0]} : align_rddata;
+ end
+ end
+ `LSR_STRB_WR:
+ next_write_reg = 1'b0;
+ `LSR_BASEWB: begin
+ next_write_reg = 1'b1;
+ next_write_num = insn[19:16];
+ next_write_data = addr;
+ end
+ `LSR_WBFLUSH:
+ next_write_reg = 1'b0;
+ default: begin end
+ endcase
+ end
+ `DECODE_LDMSTM: if(!inbubble) begin
+ next_write_reg = 1'bx;
+ next_write_num = 4'bxxxx;
+ next_write_data = 32'hxxxxxxxx;
+ case(lsm_state)
+ `LSM_SETUP:
+ next_write_reg = 1'b0;
+ `LSM_MEMIO: begin
+ if(insn[20]) begin
+ next_write_reg = !rw_wait;
+ next_write_num = cur_reg;
+ next_write_data = rd_data;
+ end else
+ next_write_reg = 1'b0;
+ end
+ `LSM_BASEWB: begin
+ next_write_reg = insn[21] /* writeback */;
+ next_write_num = insn[19:16];
+ next_write_data = insn[23] ? op0 + {26'b0, prev_offset} : op0 - {26'b0, prev_offset};
+ if(cur_reg == 4'hF && insn[22]) begin
+ next_outcpsr = spsr;
+ next_outcpsrup = 1;
+ end
+ end
+ `LSM_WBFLUSH:
+ next_write_reg = 1'b0;
+ default: begin end
+ endcase
+ end
+ `DECODE_MRCMCR: if(!inbubble) begin
+ next_write_reg = 1'bx;
+ next_write_num = 4'bxxxx;
+ next_write_data = 32'hxxxxxxxx;
+ next_outcpsr = 32'hxxxxxxxx;
+ next_outcpsrup = 1'bx;
+ if (insn[20] == 1 /* load from coprocessor */)
+ if (insn[15:12] != 4'hF /* Fuck you ARM */) begin
+ next_write_reg = 1'b1;
+ next_write_num = insn[15:12];
+ next_write_data = cp_read;
+ end else begin
+ next_outcpsr = {cp_read[31:28], cpsr[27:0]};
+ next_outcpsrup = 1;
+ end
+ end
+ endcase
+ end
+
+ /* Bus control logic. */
+ always @(*)
+ begin
+ rd_req = 1'b0;
+ wr_req = 1'b0;
+ wr_data = 32'hxxxxxxxx;
+ busaddr = 32'hxxxxxxxx;
+ data_size = 3'bxxx;
+
casez(insn)
`DECODE_ALU_SWP: if(!inbubble) begin
- next_outbubble = rw_wait;
busaddr = {op0[31:2], 2'b0};
data_size = insn[22] ? 3'b001 : 3'b100;
case(swp_state)
- `SWP_READING: begin
+ `SWP_READING:
rd_req = 1'b1;
- if(!rw_wait) begin
- next_swp_oldval = rd_data;
- end
- end
`SWP_WRITING: begin
wr_req = 1'b1;
wr_data = insn[22] ? {4{op1[7:0]}} : op1;
- next_write_reg = 1'b1;
- next_write_num = insn[15:12];
- next_write_data = insn[22] ? {24'b0, swp_oldval[7:0]} : swp_oldval;
end
default: begin end
endcase
`DECODE_ALU_MULT: begin end
`DECODE_ALU_HDATA_REG,
`DECODE_ALU_HDATA_IMM: if(!inbubble) begin
- next_outbubble = rw_wait;
- addr = insn[23] ? op0 + op1 : op0 - op1; /* up/down select */
- raddr = insn[24] ? op0 : addr; /* pre/post increment */
busaddr = raddr;
/* rotate to correct position */
case(insn[6:5])
2'b01: begin /* unsigned half */
wr_data = {2{op2[15:0]}}; /* XXX need to store halfword */
data_size = 3'b010;
- lsrh_rddata = {16'b0, raddr[1] ? rd_data[31:16] : rd_data[15:0]};
end
2'b10: begin /* signed byte */
wr_data = {4{op2[7:0]}};
data_size = 3'b001;
- lsrh_rddata_s1 = raddr[1] ? rd_data[31:16] : rd_data[15:0];
- lsrh_rddata_s2 = raddr[0] ? lsrh_rddata_s1[15:8] : lsrh_rddata_s1[7:0];
- lsrh_rddata = {{24{lsrh_rddata_s2[7]}}, lsrh_rddata_s2};
end
2'b11: begin /* signed half */
wr_data = {2{op2[15:0]}};
data_size = 3'b010;
- lsrh_rddata = raddr[1] ? {{16{rd_data[31]}}, rd_data[31:16]} : {{16{rd_data[15]}}, rd_data[15:0]};
end
default: begin
wr_data = 32'hxxxxxxxx;
data_size = 3'bxxx;
- lsrh_rddata = 32'hxxxxxxxx;
end
endcase
-
+
case(lsrh_state)
`LSRH_MEMIO: begin
rd_req = insn[20];
wr_req = ~insn[20];
- next_write_num = insn[15:12];
- next_write_data = lsrh_rddata;
- if(insn[20]) begin
- next_write_reg = 1'b1;
- end
- end
- `LSRH_BASEWB: begin
- next_outbubble = 1'b0;
- next_write_reg = 1'b1;
- next_write_num = insn[19:16];
- next_write_data = addr;
- end
- `LSRH_WBFLUSH: begin
end
+ `LSRH_BASEWB: begin end
+ `LSRH_WBFLUSH: begin end
default: begin end
endcase
end
`DECODE_LDRSTR_UNDEFINED: begin end
`DECODE_LDRSTR: if(!inbubble) begin
- next_outbubble = rw_wait;
- addr = insn[23] ? op0 + op1 : op0 - op1; /* up/down select */
- raddr = insn[24] ? addr : op0; /* pre/post increment */
busaddr = raddr;
- /* rotate to correct position */
- align_s1 = raddr[1] ? {rd_data[15:0], rd_data[31:16]} : rd_data;
- align_s2 = raddr[0] ? {align_s1[7:0], align_s1[31:8]} : align_s1;
- /* select byte or word */
- align_rddata = insn[22] ? {24'b0, align_s2[7:0]} : align_s2;
wr_data = insn[22] ? {24'h0, {op2[7:0]}} : op2;
data_size = insn[22] ? 3'b001 : 3'b100;
- case(lsr_state)
+ case (lsr_state)
`LSR_MEMIO: begin
rd_req = insn[20] /* L */ || insn[22] /* B */;
wr_req = !insn[20] /* L */ && !insn[22]/* B */;
- next_write_reg = insn[20] /* L */;
- next_write_num = insn[15:12];
- if(insn[20] /* L */) begin
- next_write_data = insn[22] /* B */ ? {24'h0, align_rddata[7:0]} : align_rddata;
- end
- if (insn[22] /* B */ && !insn[20] /* L */) begin
- do_rd_data_latch = 1;
- end
end
`LSR_STRB_WR: begin
- rd_req = 0;
wr_req = 1;
- next_write_reg = 0;
case (busaddr[1:0])
2'b00: wr_data = {rd_data_latch[31:8], op2[7:0]};
2'b01: wr_data = {rd_data_latch[31:16], op2[7:0], rd_data_latch[7:0]};
2'b11: wr_data = {op2[7:0], rd_data_latch[23:0]};
endcase
end
- `LSR_BASEWB: begin
- rd_req = 0;
- wr_req = 0;
- next_outbubble = 0;
- next_write_reg = 1'b1;
- next_write_num = insn[19:16];
- next_write_data = addr;
+ `LSR_BASEWB: begin end
+ `LSR_WBFLUSH: begin end
+ default: begin end
+ endcase
+ end
+ `DECODE_LDMSTM: if (!inbubble) begin
+ data_size = 3'b100;
+ case (lsm_state)
+ `LSM_SETUP: begin end
+ `LSM_MEMIO: begin
+ rd_req = insn[20];
+ wr_req = ~insn[20];
+ wr_data = (cur_reg == 4'hF) ? (pc + 12) : st_data;
+ busaddr = raddr;
end
- `LSR_WBFLUSH: begin
- rd_req = 0;
- wr_req = 0;
+ `LSM_BASEWB: begin end
+ `LSM_WBFLUSH: begin end
+ default: begin end
+ endcase
+ end
+ `DECODE_LDCSTC: begin end
+ `DECODE_CDP: begin end
+ `DECODE_MRCMCR: begin end
+ default: begin end
+ endcase
+ end
+
+ always @(*)
+ begin
+ addr = prevaddr;
+ raddr = 32'hxxxxxxxx;
+ st_read = 4'hx;
+ do_rd_data_latch = 0;
+
+ next_outbubble = inbubble;
+ next_regs = regs;
+
+ offset = prev_offset;
+ lsrh_rddata = 32'hxxxxxxxx;
+ lsrh_rddata_s1 = 16'hxxxx;
+ lsrh_rddata_s2 = 8'hxx;
+ next_swp_oldval = swp_oldval;
+ cur_reg = prev_reg;
+
+ /* XXX shit not given about endianness */
+ casez(insn)
+ `DECODE_ALU_SWP: if(!inbubble) begin
+ next_outbubble = rw_wait;
+ case(swp_state)
+ `SWP_READING:
+ if(!rw_wait)
+ next_swp_oldval = rd_data;
+ `SWP_WRITING: begin end
+ default: begin end
+ endcase
+ end
+ `DECODE_ALU_MULT: begin end
+ `DECODE_ALU_HDATA_REG,
+ `DECODE_ALU_HDATA_IMM: if(!inbubble) begin
+ next_outbubble = rw_wait;
+ addr = insn[23] ? op0 + op1 : op0 - op1; /* up/down select */
+ raddr = insn[24] ? op0 : addr; /* pre/post increment */
+ /* rotate to correct position */
+ case(insn[6:5])
+ 2'b01: begin /* unsigned half */
+ lsrh_rddata = {16'b0, raddr[1] ? rd_data[31:16] : rd_data[15:0]};
+ end
+ 2'b10: begin /* signed byte */
+ lsrh_rddata_s1 = raddr[1] ? rd_data[31:16] : rd_data[15:0];
+ lsrh_rddata_s2 = raddr[0] ? lsrh_rddata_s1[15:8] : lsrh_rddata_s1[7:0];
+ lsrh_rddata = {{24{lsrh_rddata_s2[7]}}, lsrh_rddata_s2};
+ end
+ 2'b11: begin /* signed half */
+ lsrh_rddata = raddr[1] ? {{16{rd_data[31]}}, rd_data[31:16]} : {{16{rd_data[15]}}, rd_data[15:0]};
end
+ default: begin
+ lsrh_rddata = 32'hxxxxxxxx;
+ end
+ endcase
+
+ case(lsrh_state)
+ `LSRH_MEMIO: begin end
+ `LSRH_BASEWB:
+ next_outbubble = 1'b0;
+ `LSRH_WBFLUSH: begin end
+ default: begin end
+ endcase
+ end
+ `DECODE_LDRSTR_UNDEFINED: begin end
+ `DECODE_LDRSTR: if(!inbubble) begin
+ next_outbubble = rw_wait;
+ addr = insn[23] ? op0 + op1 : op0 - op1; /* up/down select */
+ raddr = insn[24] ? addr : op0; /* pre/post increment */
+ /* rotate to correct position */
+ align_s1 = raddr[1] ? {rd_data[15:0], rd_data[31:16]} : rd_data;
+ align_s2 = raddr[0] ? {align_s1[7:0], align_s1[31:8]} : align_s1;
+ /* select byte or word */
+ align_rddata = insn[22] ? {24'b0, align_s2[7:0]} : align_s2;
+ case(lsr_state)
+ `LSR_MEMIO:
+ if (insn[22] /* B */ && !insn[20] /* L */)
+ do_rd_data_latch = 1;
+ `LSR_STRB_WR: begin end
+ `LSR_BASEWB:
+ next_outbubble = 0;
+ `LSR_WBFLUSH: begin end
default: begin end
endcase
end
/* XXX ldm/stm incorrect in that stupid case where one of the listed regs is the base reg */
`DECODE_LDMSTM: if(!inbubble) begin
next_outbubble = rw_wait;
- data_size = 3'b100;
case(lsm_state)
`LSM_SETUP: begin
// next_regs = insn[23] ? op1[15:0] : op1[0:15];
offset = 6'b0;
end
`LSM_MEMIO: begin
- rd_req = insn[20];
- wr_req = ~insn[20];
casez(regs)
16'b???????????????1: begin
cur_reg = 4'h0;
end
endcase
cur_reg = insn[23] ? cur_reg : 4'hF - cur_reg;
- if(cur_reg == 4'hF && insn[22]) begin
- next_outcpsr = spsr;
- next_outcpsrup = 1;
- end
offset = prev_offset + 6'h4;
offset_sel = insn[24] ? offset : prev_offset;
raddr = insn[23] ? op0 + {26'b0, offset_sel} : op0 - {26'b0, offset_sel};
- if(insn[20]) begin
- next_write_reg = !rw_wait;
- next_write_num = cur_reg;
- next_write_data = rd_data;
- end
if (rw_wait) begin
next_regs = regs;
cur_reg = prev_reg; /* whoops, do this one again */
end
st_read = cur_reg;
- wr_data = (cur_reg == 4'hF) ? (pc + 12) : st_data;
- busaddr = raddr;
end
- `LSM_BASEWB: begin
+ `LSM_BASEWB:
next_outbubble = 0;
- next_write_reg = insn[21] /* writeback */;
- next_write_num = insn[19:16];
- next_write_data = insn[23] ? op0 + {26'b0, prev_offset} : op0 - {26'b0, prev_offset};
- end
`LSM_WBFLUSH: begin end
default: $stop;
endcase
end
`DECODE_LDCSTC: begin end
`DECODE_CDP: if(!inbubble) begin
- cp_req = 1;
if (cp_busy) begin
next_outbubble = 1;
end
- if (!cp_ack) begin
- /* XXX undefined instruction trap */
- $display("WARNING: Possible CDP undefined instruction");
- end
end
`DECODE_MRCMCR: if(!inbubble) begin
- cp_req = 1;
- cp_rnw = insn[20] /* L */;
- if (insn[20] == 0 /* store to coprocessor */)
- cp_write = op0;
- else begin
- if (insn[15:12] != 4'hF /* Fuck you ARM */) begin
- next_write_reg = 1'b1;
- next_write_num = insn[15:12];
- next_write_data = cp_read;
- end else begin
- next_outcpsr = {cp_read[31:28], cpsr[27:0]};
- next_outcpsrup = 1;
- end
- end
if (cp_busy) begin
next_outbubble = 1;
end
- if (!cp_ack) begin
- $display("WARNING: Possible MRCMCR undefined instruction: cp_ack %d, cp_busy %d",cp_ack, cp_busy);
- end
end
default: begin end
endcase
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