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2 Commits
619702384b ... cac01f0333

Author SHA1 Message Date
(Tim) Efthimis Kritikos
cac01f0333 Fixed Makefile bug 2023-02-22 01:51:14 +00:00
(Tim) Efthimis Kritikos
7fde422341 Added Microcode support, Stack, implemented the CALL instruction in microcode and grouped the wires on the decoder module 2023-02-22 01:28:23 +00:00
13 changed files with 625 additions and 431 deletions
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10
Makefile
View File

@ -19,14 +19,16 @@
SYSTEM_VVP=system/system.vvp
BOOT_CODE=boot_code/brainfuck.txt
GTKWSAVE=./gtkwave_savefile.gtkw
MICROCODE=system/ucode.hex
MICROCODE=system/ucode.txt
BOOTABLES=boot_code/brainfuck_compiled.txt boot_code/brainfuck_mandelbrot.txt ${BOOT_CODE}
NO_ASM=1
include common.mk
.PHONY: ${BOOTABLES}
.PHONY: ${subst .txt,.bin,${BOOTABLES}}
.PHONY:${BOOT_CODE}
${BOOT_CODE}:
${BOOTABLES} ${subst .txt,.bin,${BOOTABLES}} :
${Q}make ${MAKEOPTS} -C boot_code $(subst boot_code/,,$@)
boot_code/%.txt:

1
boot_code/Makefile
View File

@ -11,6 +11,7 @@ brainfuck.bin: brainfuck_interpreter_v0.asm
brainfuck_mandelbrot.bin: brainfuck_interpreter_v0.asm
brainfuck_compiled.bin: brainfuck_compiler_v1.asm
NO_ASM=0
include ../common.mk
clean:

3
boot_code/brainfuck_compiler_v1.asm
View File

@ -17,6 +17,7 @@
; You should have received a copy of the GNU General Public License
; along with this program. If not, see <http://www.gnu.org/licenses/>.
mov sp,#STACK
mov bx,#bootup_msg
mov ah,#0x02
bootup_print:
@ -239,4 +240,6 @@ RET
bootup_msg: .ASCII 'Native brainfuck compiler v1\n'
DATA: .BLKB 560
.BLKB 200
STACK:
output_program: .BLKB 600

2
common.mk
View File

@ -27,9 +27,11 @@ disas: $(subst .txt,.disas,${BOOT_CODE})
${Q}xxd -ps -c 2 "$(subst .bin,.stage,$<)" > "$@"
${Q}rm "$(subst .bin,.stage,$<)"
ifeq "${NO_ASM}" "0"
%.bin:%.asm
${QUIET_AS}
${Q}as86 -0 "$<" -b "$@"
endif
# Running simulation
%.lx2 %.memdump: %.txt ${SYSTEM_VVP}

26
gtkwave_savefile.gtkw
View File

@ -1,35 +1,37 @@
[*]
[*] GTKWave Analyzer v3.3.104 (w)1999-2020 BSI
[*] Tue Feb 14 12:39:46 2023
[*] Tue Feb 21 04:41:50 2023
[*]
[dumpfile] "/home/user/UNI_DATA/COMS30046_2022_TB-2/projects/9086/cpu/test.lx2"
[dumpfile_mtime] "Tue Feb 14 12:37:32 2023"
[dumpfile_size] 1922
[savefile] "/home/user/UNI_DATA/COMS30046_2022_TB-2/projects/9086/cpu/gtkwave_savefile.gtkw"
[timestart] 0
[size] 1438 1059
[dumpfile] "/home/user/UNI_DATA/COMS30046_2022_TB-2/projects/9086/boot_code/brainfuck_compiled.lx2"
[dumpfile_mtime] "Tue Feb 21 04:40:18 2023"
[dumpfile_size] 21374
[savefile] "/home/user/UNI_DATA/COMS30046_2022_TB-2/projects/9086/gtkwave_savefile.gtkw"
[timestart] 513190000
[size] 1342 1059
[pos] -1 -1
*-23.795050 41712000 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
*-23.795050 802940000 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
[treeopen] tb.
[treeopen] tb.p.
[sst_width] 221
[signals_width] 293
[sst_expanded] 1
[sst_vpaned_height] 313
[sst_vpaned_height] 312
@28
tb.p.clock[0]
tb.p.reset[0]
tb.p.state[4:0]
tb.p.state[5:0]
@23
tb.p.ucode_seq_addr[4:0]
@22
tb.p.external_address_bus[19:0]
tb.p.external_data_bus[15:0]
tb.p.CIR[15:0]
tb.p.PARAM1[15:0]
tb.p.PARAM2[15:0]
@29
tb.p.read[0]
@28
tb.p.read[0]
tb.p.write[0]
tb.p.ERROR[0]
tb.p.SIMPLE_MICRO[0]
[pattern_trace] 1
[pattern_trace] 0

5
system/Makefile
View File

@ -16,12 +16,13 @@
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
SOURCES=processor.v testbench.v memory.v registers.v alu.v decoder.v general.v
INCLUDES=proc_state_def.v alu_header.v config.v ucode_header.v ucode.hex
INCLUDES=proc_state_def.v alu_header.v config.v ucode_header.v ${MICROCODE}
SYSTEM_VVP=system.vvp
BOOT_CODE=boot_code.txt
GTKWSAVE=../gtkwave_savefile.gtkw
MICROCODE=ucode.hex
MICROCODE=ucode.txt
NO_ASM=0
include ../common.mk
# COMPILING

703
system/decoder.v
View File

@ -43,16 +43,31 @@ assign DATA=ucode[ADDR];
endmodule
module decoder(
input wire [15:0] CIR,input wire [15:0] FLAGS, output reg Wbit, output reg Sbit, output reg unaligning ,output reg opcode_size, output reg ERROR,output reg [`PROC_STATE_BITS-1:0]next_state
,output reg [1:0]MOD, output reg [2:0]RM, output reg [15:0] PARAM1,output reg [15:0] PARAM2,output reg HALT,output reg has_operands
input wire [15:0] CIR,input wire [15:0] FLAGS, output wire [4:0] INSTRUCTION_INFO, output wire [1:0]DECODER_SIGNALS,output reg [`PROC_STATE_BITS-1:0]next_state
,output reg [1:0]MOD, output reg [2:0]RM, output reg [15:0] PARAM1,output reg [15:0] PARAM2
,output reg [1:0]in_alu1_sel1,output reg [1:0]in_alu1_sel2,output reg [2:0]out_alu1_sel
,output reg [3:0]reg_read_port1_addr, output reg [3:0]reg_write_addr
,output wire [11:0]REGISTER_FILE_CONTROL
,output reg [2:0]ALU_1OP
,output reg [`UCODE_ADDR_BITS-1:0] seq_addr_entry, input wire SIMPLE_MICRO, input wire [`UCODE_ADDR_BITS-1:0] seq_addr_input
);
reg [3:0]reg_read_port1_addr;
reg [3:0]reg_read_port2_addr;
reg [3:0]reg_write_addr;
assign REGISTER_FILE_CONTROL={reg_write_addr,reg_read_port1_addr,reg_read_port2_addr};
/* For correct fetching of instructions and global options for the alu */
reg Wbit,Sbit,unaligning,opcode_size,has_operands;
assign INSTRUCTION_INFO={Wbit,Sbit,unaligning,opcode_size,has_operands};
reg ERROR, HALT;
assign DECODER_SIGNALS={ERROR,HALT};
wire [`UCODE_DATA_BITS-1:0] ucode_data;
reg [`UCODE_ADDR_BITS-1:0] UCODE_ADDR;
microcode ucode(UCODE_ADDR,ucode_data);
microcode ucode(seq_addr_input,ucode_data);
/* 0 0 0 0 0 0 0 0 | 0 0 0 0 0 0 0 0 | 0 0 0 0 0 0 0 0 | 0 0 0 0 0 0 0 0 */
@ -61,325 +76,379 @@ microcode ucode(UCODE_ADDR,ucode_data);
`define start_unaligning_instruction unaligning=1;
always @( CIR ) begin
ERROR=0;HALT=0;
casex({CIR[15:8],CIR[5:3]})
11'b0000_010x_xxx : begin
/* Add Immediate word/byte to accumulator */
/* 0 0 0 0 0 1 0 W | DATA | DATA if W |*/
opcode_size=0;
has_operands=1;
Wbit=CIR[8:8];
if(Wbit)
`start_unaligning_instruction
else
`start_aligning_instruction
MOD=2'b11;
in_alu1_sel1=2'b00;
in_alu1_sel2=2'b01;
out_alu1_sel=3'b011;
reg_read_port1_addr={Wbit,3'b000};
reg_write_addr={Wbit,3'b000};
ALU_1OP=`ALU_OP_ADD;
if(Wbit==1)
next_state=`PROC_DE_LOAD_16_PARAM;
else begin
PARAM1[7:0]=CIR[7:0];
next_state=`PROC_EX_STATE_ENTRY;
end
end
11'b1000_00xx_000 : begin
/* Add Immediate word/byte to register/memory */
/* 1 0 0 0 0 0 S W | MOD 0 0 0 R/M | < DISP LO > | < DISP HI > | DATA | DATA if W | */
`start_aligning_instruction
opcode_size=1;
has_operands=1;
Wbit=CIR[8:8];
Sbit=CIR[9:9];
MOD=2'b11;
in_alu1_sel1=2'b00;
in_alu1_sel2=2'b01;
out_alu1_sel={1'b0,MOD};
reg_read_port1_addr={Wbit,RM};
reg_write_addr={Wbit,RM};
ALU_1OP=`ALU_OP_ADD;
next_state=`PROC_DE_LOAD_16_PARAM;
if(Wbit==1)
next_state=`PROC_DE_LOAD_16_PARAM;
else begin
`invalid_instruction /*do 8bit loads*/
end
end
11'b1000_00xx_111 : begin
/* CMP - compare Immediate with register / memory */
/* 1 0 0 0 0 0 S W | MOD 1 1 1 R/M | < DISP LO > | < DISP HI > | DATA | DATA if W | */
opcode_size=1;
has_operands=1;
Wbit=CIR[8:8];
Sbit=CIR[9:9];
MOD=CIR[7:6];
RM=CIR[2:0];
if(((Wbit==1)&&(Sbit==1))||Wbit==0)begin
`start_unaligning_instruction
end else begin
`invalid_instruction;
end
if(MOD==2'b11)begin
always @( CIR or SIMPLE_MICRO or seq_addr_input ) begin
if (SIMPLE_MICRO==0)begin
ERROR=0;HALT=0;
casex({CIR[15:8],CIR[5:3]})
11'b0000_010x_xxx : begin
/* Add Immediate word/byte to accumulator */
/* 0 0 0 0 0 1 0 W | DATA | DATA if W |*/
seq_addr_entry=`UCODE_NO_INSTRUCTION;
opcode_size=0;
has_operands=1;
Wbit=CIR[8:8];
if(Wbit)
`start_unaligning_instruction
else
`start_aligning_instruction
MOD=2'b11;
in_alu1_sel1=2'b00;
in_alu1_sel2=2'b01;
reg_read_port1_addr={Wbit,RM};
out_alu1_sel=3'b011;
reg_read_port2_addr={Wbit,3'b000};
reg_write_addr={Wbit,3'b000};
ALU_1OP=`ALU_OP_ADD;
if(Wbit==1)
next_state=`PROC_DE_LOAD_16_PARAM;
else begin
PARAM1[7:0]=CIR[7:0];
next_state=`PROC_EX_STATE_ENTRY;
end
end
11'b1000_00xx_000 : begin
/* Add Immediate word/byte to register/memory */
/* 1 0 0 0 0 0 S W | MOD 0 0 0 R/M | < DISP LO > | < DISP HI > | DATA | DATA if W | */
seq_addr_entry=`UCODE_NO_INSTRUCTION;
`start_aligning_instruction
opcode_size=1;
has_operands=1;
Wbit=CIR[8:8];
Sbit=CIR[9:9];
MOD=2'b11;
in_alu1_sel1=2'b00;
in_alu1_sel2=2'b01;
out_alu1_sel={1'b0,MOD};
reg_read_port2_addr={Wbit,RM};
reg_write_addr={Wbit,RM};
ALU_1OP=`ALU_OP_ADD;
next_state=`PROC_DE_LOAD_16_PARAM;
if(Wbit==1)
next_state=`PROC_DE_LOAD_16_PARAM;
else begin
`invalid_instruction /*do 8bit loads*/
end
end
11'b1000_00xx_111 : begin
/* CMP - compare Immediate with register / memory */
/* 1 0 0 0 0 0 S W | MOD 1 1 1 R/M | < DISP LO > | < DISP HI > | DATA | DATA if W | */
seq_addr_entry=`UCODE_NO_INSTRUCTION;
opcode_size=1;
has_operands=1;
Wbit=CIR[8:8];
Sbit=CIR[9:9];
MOD=CIR[7:6];
RM=CIR[2:0];
if(((Wbit==1)&&(Sbit==1))||Wbit==0)begin
`start_unaligning_instruction
end else begin
`invalid_instruction;
end
if(MOD==2'b11)begin
in_alu1_sel1=2'b00;
in_alu1_sel2=2'b01;
reg_read_port2_addr={Wbit,RM};
out_alu1_sel=3'b100;
ALU_1OP=`ALU_OP_SUB;
next_state=`PROC_DE_LOAD_8_PARAM;
end else begin
`invalid_instruction
end
end
11'b1011_0xxx_xxx : begin
/* MOV - Move Immediate byte to register */
/* 1 0 1 1 W REG | DATA | DATA if W |*/
seq_addr_entry=`UCODE_NO_INSTRUCTION;
`start_aligning_instruction
has_operands=1;
Wbit=CIR[11:11]; /* IS 0 */
opcode_size=0;
MOD=2'b11;
in_alu1_sel1=2'b00;
in_alu1_sel2=2'b00;
out_alu1_sel=3'b011;
reg_write_addr={1'b0,CIR[10:8]};
PARAM1[7:0]=CIR[7:0];
PARAM2=0;
ALU_1OP=`ALU_OP_ADD;
next_state=`PROC_EX_STATE_ENTRY;
end
11'b1011_1xxx_xxx : begin
/*MOV - Move Immediate word to register*/
seq_addr_entry=`UCODE_NO_INSTRUCTION;
`start_unaligning_instruction
has_operands=1;
Wbit=CIR[11:11]; /*IS 1 */
opcode_size=0;
MOD=2'b11;
in_alu1_sel1=2'b00;
in_alu1_sel2=2'b00;
out_alu1_sel=3'b011;
reg_write_addr={1'b1,CIR[10:8]};
ALU_1OP=`ALU_OP_ADD;
PARAM2=0;
next_state=`PROC_DE_LOAD_16_PARAM;
end
11'b1000_10xx_xxx : begin
/* MOV - Reg/Mem to/from register */
/* 1 0 0 0 1 0 D W | MOD REG RM | < DISP LO > | < DISP HI > |*/
seq_addr_entry=`UCODE_NO_INSTRUCTION;
has_operands=0;
`start_aligning_instruction
opcode_size=1;
MOD=CIR[7:6];
RM=CIR[2:0];
Wbit=CIR[8:8];
in_alu1_sel2=2'b00;
if(CIR[9:9] == 1)begin
/* Mem/Reg to reg */
if(MOD==2'b11)begin
/*Reg to Reg*/
in_alu1_sel1=2'b01;
reg_read_port1_addr={Wbit,RM};
next_state=`PROC_EX_STATE_ENTRY;
end else begin
/*Mem to Reg*/
in_alu1_sel1=2'b00;
next_state=`RPOC_MEMIO_READ;
end
out_alu1_sel=3'b011;
reg_write_addr={Wbit,CIR[5:3]};
end else begin
/* Reg to Mem/Reg */
if(MOD==2'b11)begin
/*Reg to Reg*/
in_alu1_sel1=2'b01;
out_alu1_sel=3'b011;
reg_write_addr={Wbit,RM};
next_state=`PROC_EX_STATE_ENTRY;
end else begin
/*Reg to Mem*/
in_alu1_sel1=2'b00;
reg_read_port1_addr={Wbit,CIR[5:3]};
out_alu1_sel={1'b0,MOD};
next_state=`PROC_DE_LOAD_REG_TO_PARAM;
end
reg_read_port1_addr={Wbit,CIR[5:3]};
end
ALU_1OP=`ALU_OP_ADD;
PARAM2=0;
end
11'b0100_xxxx_xxx:begin//DEC
/* DEC - Decrement Register */
/* | 0 1 0 0 1 REG | */
/* INC - Increment Register */
/* | 0 1 0 0 0 REG | */
seq_addr_entry=`UCODE_NO_INSTRUCTION;
has_operands=0;
opcode_size=0;
`start_unaligning_instruction
Wbit=1;
in_alu1_sel1=2'b01;
in_alu1_sel2=2'b00;
out_alu1_sel=3'b011;
MOD=2'b11;
PARAM2=1;
reg_read_port1_addr={1'b1,CIR[10:8]};
reg_write_addr={1'b1,CIR[10:8]};
if(CIR[11:11]==0)
ALU_1OP=`ALU_OP_ADD;
else
ALU_1OP=`ALU_OP_SUB;
next_state=`PROC_EX_STATE_ENTRY;
end
11'b1111_111x_00x : begin
/* INC - Register/Memory */
/* 1 1 1 1 1 1 1 W | MOD 0 0 0 R/M | < DISP LO> | < DISP HI> */
/* DEC - Register/Memory */
/* 1 1 1 1 1 1 1 W | MOD 0 0 1 R/M | < DISP LO> | < DISP HI> */
seq_addr_entry=`UCODE_NO_INSTRUCTION;
has_operands=1;
opcode_size=1;
`start_aligning_instruction
Wbit=CIR[8:8];
MOD=CIR[7:6];
RM=CIR[2:0];
in_alu1_sel1=(MOD==2'b11)? 2'b01 : 2'b00;
in_alu1_sel2=2'b00;/* number 1 */
PARAM2=1;
out_alu1_sel={1'b0,MOD};
/*in case MOD=11 */
reg_read_port1_addr={1'b0,RM};
reg_write_addr={1'b0,RM};
ALU_1OP=(CIR[3:3]==1)?`ALU_OP_SUB:`ALU_OP_ADD;
if ( MOD == 2'b11 )
next_state=`PROC_EX_STATE_ENTRY;
else
next_state=`RPOC_MEMIO_READ;
end
11'b1111_0100_xxx : begin
/* HLT - Halt */
/* 1 1 1 1 0 1 0 0 | */
seq_addr_entry=`UCODE_NO_INSTRUCTION;
has_operands=0;
opcode_size=0;
`start_unaligning_instruction
MOD=2'b11;
HALT=1;
next_state=`PROC_HALT_STATE;
end
11'b0011_110x_xxx : begin
/* CMP - Compare Immediate with accumulator */
/* 0 0 1 1 1 1 0 W | DATA | DATA if W |*/
/* */
/* NOTE: 8086 doc doesn't show the third byte but the */
/* W flag and my assembler seem to disagree */
seq_addr_entry=`UCODE_NO_INSTRUCTION;
Wbit=CIR[8:8];
opcode_size=0;
has_operands=1;
if(Wbit)
`start_unaligning_instruction
else
`start_aligning_instruction
MOD=2'b11;
in_alu1_sel1=2'b00;
in_alu1_sel2=2'b01;
reg_read_port2_addr={Wbit,3'b000};
out_alu1_sel=3'b100;
ALU_1OP=`ALU_OP_SUB;
next_state=`PROC_DE_LOAD_8_PARAM;
end else begin
if(Wbit==1)
next_state=`PROC_DE_LOAD_16_PARAM;
else begin
PARAM1[7:0]=CIR[7:0];
next_state=`PROC_EX_STATE_ENTRY;
end
end
11'b0111_xxxx_xxx:begin
/* Conditional relative jumps */
/* JE/JZ - Jump on Zero */
/* 0 1 1 1 0 1 0 0 | IP-INC8 |*/
/* JS - Jump on Sign */
/* 0 1 1 1 1 0 0 0 | IP-INC8 |*/
/* JNS -Jump on not Sign */
/* 0 1 1 1 1 0 0 1 | IP-INC8 |*/
/* .... */
seq_addr_entry=`UCODE_NO_INSTRUCTION;
has_operands=1;
`start_aligning_instruction
Wbit=1;
opcode_size=0;
in_alu1_sel1=2'b10;
in_alu1_sel2=2'b00;
PARAM2={{8{CIR[7:7]}},CIR[7:0]};
ALU_1OP=`ALU_OP_ADD_SIGNED_B;
out_alu1_sel=3'b101;
case(CIR[11:9])
3'b000: begin
/* Jump on (not) Overflow */
if(FLAGS[11:11]==CIR[8:8])
next_state=`PROC_IF_STATE_ENTRY;
else begin
next_state=`PROC_EX_STATE_ENTRY;
end
end
3'b010: begin
/* Jump on (not) Zero */
if(FLAGS[6:6]==CIR[8:8])
next_state=`PROC_IF_STATE_ENTRY;
else
next_state=`PROC_EX_STATE_ENTRY;
end
3'b100: begin
/* Jump on (not) Sign */
if(FLAGS[7:7]==CIR[8:8])
next_state=`PROC_IF_STATE_ENTRY;
else
next_state=`PROC_EX_STATE_ENTRY;
end
3'b101: begin
/* Jump on (not) Parity */
if(FLAGS[2:2]==CIR[8:8])
next_state=`PROC_IF_STATE_ENTRY;
else
next_state=`PROC_EX_STATE_ENTRY;
end
default:begin
`invalid_instruction; /*We don't support that condition*/
end
endcase
end
11'b1110_1011_xxx:begin
/* JMP - Unconditional jump direct within segment (short) */
/* | 1 1 1 0 1 0 1 1 | IP-INC-LO | */
seq_addr_entry=`UCODE_NO_INSTRUCTION;
`start_aligning_instruction
opcode_size=0;
has_operands=1;
Wbit=1;
in_alu1_sel1=2'b10;
in_alu1_sel2=2'b00;
PARAM2={{8{CIR[7:7]}},CIR[7:0]};
ALU_1OP=`ALU_OP_ADD_SIGNED_B;
out_alu1_sel=3'b101;
next_state=`PROC_EX_STATE_ENTRY;
end
11'b1100_1101_xxx:begin
/* INT - execute interrupt handler */
/* 1 1 0 0 1 1 0 1 | DATA |*/
seq_addr_entry=`UCODE_NO_INSTRUCTION;
has_operands=1;
opcode_size=0;
`start_aligning_instruction
/* Emulate MS-DOS print routines */
if(CIR[7:0]==8'h21 && register_file.registers[0][15:8]==8'h02)begin
$write("%s" ,register_file.registers[2][7:0]); /*TODO:Could trigger erroneously while CIR is not final*/
end
next_state=`PROC_IF_STATE_ENTRY;
end
11'b11101000_xxx:begin
/* CALL - Direct call within segment */
/* 1 1 1 0 1 0 0 0 | IP-INC-LO | IP-INC-HI |*/
// Microcode instruction
`start_unaligning_instruction
opcode_size=0;
has_operands=1;
Wbit=1;
Sbit=1;
PARAM2=2; //substract from sp
seq_addr_entry=`UCODE_CALL_ENTRY;
end
default:begin
`invalid_instruction
end
end
11'b1011_0xxx_xxx : begin
/* MOV - Move Immediate byte to register */
/* 1 0 1 1 W REG | DATA | DATA if W |*/
`start_aligning_instruction
has_operands=1;
Wbit=CIR[11:11]; /* IS 0 */
opcode_size=0;
MOD=2'b11;
in_alu1_sel1=2'b00;
in_alu1_sel2=2'b00;
out_alu1_sel=3'b011;
reg_write_addr={1'b0,CIR[10:8]};
PARAM1[7:0]=CIR[7:0];
PARAM2=0;
ALU_1OP=`ALU_OP_ADD;
next_state=`PROC_EX_STATE_ENTRY;
end
11'b1011_1xxx_xxx : begin
/*MOV - Move Immediate word to register*/
`start_unaligning_instruction
has_operands=1;
Wbit=CIR[11:11]; /*IS 1 */
opcode_size=0;
MOD=2'b11;
in_alu1_sel1=2'b00;
in_alu1_sel2=2'b00;
out_alu1_sel=3'b011;
reg_write_addr={1'b1,CIR[10:8]};
ALU_1OP=`ALU_OP_ADD;
PARAM2=0;
next_state=`PROC_DE_LOAD_16_PARAM;
end
11'b1000_10xx_xxx : begin
/* MOV - Reg/Mem to/from register */
/* 1 0 0 0 1 0 D W | MOD REG RM | < DISP LO > | < DISP HI > |*/
has_operands=0;
`start_aligning_instruction
opcode_size=1;
MOD=CIR[7:6];
RM=CIR[2:0];
Wbit=CIR[8:8];
in_alu1_sel2=2'b00;
if(CIR[9:9] == 1)begin
/* Mem/Reg to reg */
if(MOD==2'b11)begin
/*Reg to Reg*/
in_alu1_sel1=2'b01;
reg_read_port1_addr={Wbit,RM};
next_state=`PROC_EX_STATE_ENTRY;
end else begin
/*Mem to Reg*/
in_alu1_sel1=2'b00;
next_state=`RPOC_MEMIO_READ;
end
out_alu1_sel=3'b011;
reg_write_addr={Wbit,CIR[5:3]};
end else begin
/* Reg to Mem/Reg */
if(MOD==2'b11)begin
/*Reg to Reg*/
in_alu1_sel1=2'b01;
out_alu1_sel=3'b011;
reg_write_addr={Wbit,RM};
next_state=`PROC_EX_STATE_ENTRY;
end else begin
/*Reg to Mem*/
in_alu1_sel1=2'b00;
reg_read_port1_addr={Wbit,CIR[5:3]};
out_alu1_sel={1'b0,MOD};
next_state=`PROC_DE_LOAD_REG_TO_PARAM;
end
reg_read_port1_addr={Wbit,CIR[5:3]};
end
ALU_1OP=`ALU_OP_ADD;
PARAM2=0;
end
11'b0100_xxxx_xxx:begin//DEC
/* DEC - Decrement Register */
/* | 0 1 0 0 1 REG | */
/* INC - Increment Register */
/* | 0 1 0 0 0 REG | */
has_operands=0;
opcode_size=0;
`start_unaligning_instruction
Wbit=1;
in_alu1_sel1=2'b01;
in_alu1_sel2=2'b00;
out_alu1_sel=3'b011;
MOD=2'b11;
PARAM2=1;
reg_read_port1_addr={1'b1,CIR[10:8]};
reg_write_addr={1'b1,CIR[10:8]};
if(CIR[11:11]==0)
ALU_1OP=`ALU_OP_ADD;
else
ALU_1OP=`ALU_OP_SUB;
next_state=`PROC_EX_STATE_ENTRY;
end
11'b1111_111x_00x : begin
/* INC - Register/Memory */
/* 1 1 1 1 1 1 1 W | MOD 0 0 0 R/M | < DISP LO> | < DISP HI> */
/* DEC - Register/Memory */
/* 1 1 1 1 1 1 1 W | MOD 0 0 1 R/M | < DISP LO> | < DISP HI> */
has_operands=1;
opcode_size=1;
`start_aligning_instruction
Wbit=CIR[8:8];
MOD=CIR[7:6];
RM=CIR[2:0];
in_alu1_sel1=(MOD==2'b11)? 2'b01 : 2'b00;
in_alu1_sel2=2'b00;/* number 1 */
PARAM2=1;
out_alu1_sel={1'b0,MOD};
/*in case MOD=11 */
reg_read_port1_addr={1'b0,RM};
reg_write_addr={1'b0,RM};
ALU_1OP=(CIR[3:3]==1)?`ALU_OP_SUB:`ALU_OP_ADD;
if ( MOD == 2'b11 )
next_state=`PROC_EX_STATE_ENTRY;
else
next_state=`RPOC_MEMIO_READ;
end
11'b1111_0100_xxx : begin
/* HLT - Halt */
/* 1 1 1 1 0 1 0 0 | */
has_operands=0;
opcode_size=0;
`start_unaligning_instruction
MOD=2'b11;
HALT=1;
next_state=`PROC_HALT_STATE;
end
11'b0011_110x_xxx : begin
/* CMP - Compare Immediate with accumulator */
/* 0 0 1 1 1 1 0 W | DATA | DATA if W |*/
/* */
/* NOTE: 8086 doc doesn't show the third byte but the */
/* W flag and my assembler seem to disagree */
Wbit=CIR[8:8];
opcode_size=0;
has_operands=1;
if(Wbit)
`start_unaligning_instruction
else
`start_aligning_instruction
MOD=2'b11;
in_alu1_sel1=2'b00;
in_alu1_sel2=2'b01;
reg_read_port1_addr={Wbit,3'b000};
out_alu1_sel=3'b100;
ALU_1OP=`ALU_OP_SUB;
if(Wbit==1)
next_state=`PROC_DE_LOAD_16_PARAM;
else begin
PARAM1[7:0]=CIR[7:0];
next_state=`PROC_EX_STATE_ENTRY;
end
end
11'b0111_xxxx_xxx:begin
/* Conditional relative jumps */
/* JE/JZ - Jump on Zero */
/* 0 1 1 1 0 1 0 0 | IP-INC8 |*/
/* JS - Jump on Sign */
/* 0 1 1 1 1 0 0 0 | IP-INC8 |*/
/* JNS -Jump on not Sign */
/* 0 1 1 1 1 0 0 1 | IP-INC8 |*/
/* .... */
has_operands=1;
`start_aligning_instruction
Wbit=1;
opcode_size=0;
in_alu1_sel1=2'b10;
in_alu1_sel2=2'b00;
PARAM2={{8{CIR[7:7]}},CIR[7:0]};
ALU_1OP=`ALU_OP_ADD_SIGNED_B;
out_alu1_sel=3'b101;
case(CIR[11:9])
3'b000: begin
/* Jump on (not) Overflow */
if(FLAGS[11:11]==CIR[8:8])
next_state=`PROC_IF_STATE_ENTRY;
else begin
next_state=`PROC_EX_STATE_ENTRY;
end
end
3'b010: begin
/* Jump on (not) Zero */
if(FLAGS[6:6]==CIR[8:8])
next_state=`PROC_IF_STATE_ENTRY;
else
next_state=`PROC_EX_STATE_ENTRY;
end
3'b100: begin
/* Jump on (not) Sign */
if(FLAGS[7:7]==CIR[8:8])
next_state=`PROC_IF_STATE_ENTRY;
else
next_state=`PROC_EX_STATE_ENTRY;
end
3'b101: begin
/* Jump on (not) Parity */
if(FLAGS[2:2]==CIR[8:8])
next_state=`PROC_IF_STATE_ENTRY;
else
next_state=`PROC_EX_STATE_ENTRY;
end
default:begin
`invalid_instruction; /*We don't support that condition*/
end
endcase
end
11'b1110_1011_xxx:begin
/* JMP - Unconditional jump direct within segment (short) */
/* | 1 1 1 0 1 0 1 1 | IP-INC-LO | */
`start_aligning_instruction
opcode_size=0;
has_operands=1;
Wbit=1;
in_alu1_sel1=2'b10;
in_alu1_sel2=2'b00;
PARAM2={{8{CIR[7:7]}},CIR[7:0]};
ALU_1OP=`ALU_OP_ADD_SIGNED_B;
out_alu1_sel=3'b101;
next_state=`PROC_EX_STATE_ENTRY;
end
11'b1100_1101_xxx:begin
/* INT - execute interrupt handler */
/* 1 1 0 0 1 1 0 1 | DATA |*/
has_operands=1;
opcode_size=0;
`start_aligning_instruction
/* Emulate MS-DOS print routines */
if(CIR[7:0]==8'h21 && register_file.registers[0][15:8]==8'h02)begin
$write("%s" ,register_file.registers[2][7:0]); /*TODO:Could trigger erroneously while CIR is not final*/
end
next_state=`PROC_IF_STATE_ENTRY;
end
default:begin
`invalid_instruction
end
endcase
endcase
end else begin
/*Microcode output*/
//Sbit, Wbit, opcode_size and the others are still latched
//from when we ordered the switch to microcode
seq_addr_entry=ucode_data[5:0];
case(ucode_data[7:6])
2'b00: next_state=`PROC_EX_STATE_ENTRY;
2'b01: next_state=`PROC_DE_LOAD_16_PARAM;
2'b10: next_state=`PROC_DE_LOAD_8_PARAM;
2'b11: next_state=`PROC_DE_LOAD_REG_TO_PARAM;
endcase
reg_write_addr=ucode_data[11:8 ];
in_alu1_sel1 =ucode_data[13:12];
in_alu1_sel2 =ucode_data[15:14];
out_alu1_sel =ucode_data[18:16];
/*1:1 map essentially but I want to keep the spec for these bits seperate
* from the alu op select bits*/
case(ucode_data[21:19])
3'b000: ALU_1OP=`ALU_OP_ADD;
3'b001: ALU_1OP=`ALU_OP_SUB;
3'b010: ALU_1OP=`ALU_OP_AND;
3'b011: ALU_1OP=`ALU_OP_OR;
3'b100: ALU_1OP=`ALU_OP_XOR;
3'b101: ALU_1OP=`ALU_OP_ADD_SIGNED_B;
endcase
reg_read_port1_addr=ucode_data[25:22];
end
end
endmodule

70
system/proc_state_def.v
View File

@ -18,49 +18,51 @@
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
`define PROC_STATE_BITS 5
`define PROC_STATE_BITS 6
`define PROC_HALT_STATE 5'b00000
`define PROC_HALT_STATE 6'b000000
/*INSTRUCTION FETCH STATE*/
`define PROC_IF_STATE_ENTRY 5'b00001
`define PROC_IF_WRITE_CIR 5'b00010
`define PROC_IF_STATE_EXTRA_FETCH_SET 5'b00011
`define PROC_IF_STATE_EXTRA_FETCH 5'b00100
`define PROC_IF_STATE_ENTRY 6'b000001
`define PROC_IF_WRITE_CIR 6'b000010
`define PROC_IF_STATE_EXTRA_FETCH_SET 6'b000011
`define PROC_IF_STATE_EXTRA_FETCH 6'b000100
/*DECODE SATE*/
`define PROC_DE_STATE_ENTRY 5'b01000
`define PROC_DE_LOAD_16_PARAM 5'b01001
`define PROC_DE_LOAD_16_EXTRA_FETCH_SET 5'b01010
`define PROC_DE_LOAD_16_EXTRA_FETCH 5'b01011
`define PROC_DE_LOAD_REG_TO_PARAM 5'b11011 /****/
`define PROC_DE_STATE_ENTRY 6'b001000
`define PROC_DE_LOAD_16_PARAM 6'b001001
`define PROC_DE_LOAD_16_EXTRA_FETCH_SET 6'b001010
`define PROC_DE_LOAD_16_EXTRA_FETCH 6'b001011
`define PROC_DE_LOAD_REG_TO_PARAM 6'b001100
/*MEM/IO READ*/
`define RPOC_MEMIO_READ 5'b10000
`define PROC_MEMIO_READ_SETADDR 5'b10001
`define PROC_MEMIO_GET_ALIGNED_DATA 5'b10010 /* :) */
`define PROC_MEMIO_GET_UNALIGNED_DATA 5'b10011 /* :( */
`define PROC_MEMIO_GET_SECOND_BYTE 5'b11100 /******/
`define PROC_MEMIO_GET_SECOND_BYTE1 5'b11101 /******/
`define PROC_DE_LOAD_8_PARAM 5'b00110 /******/
`define PROC_DE_LOAD_8_PARAM_UNALIGNED 5'b00111 /******/
`define RPOC_MEMIO_READ 6'b010000
`define PROC_MEMIO_READ_SETADDR 6'b010001
`define PROC_MEMIO_GET_ALIGNED_DATA 6'b010010 /* :) */
`define PROC_MEMIO_GET_UNALIGNED_DATA 6'b010011 /* :( */
`define PROC_MEMIO_GET_SECOND_BYTE 6'b010100
`define PROC_MEMIO_GET_SECOND_BYTE1 6'b010101
`define PROC_DE_LOAD_8_PARAM 6'b010110
`define PROC_DE_LOAD_8_PARAM_UNALIGNED 6'b010111
/*EXECUTE STATE*/
`define PROC_EX_STATE_ENTRY 5'b11000
`define PROC_EX_STATE_EXIT 5'b11001
`define PROC_EX_STATE_ENTRY 6'b100000
`define PROC_EX_STATE_EXIT 6'b100001
/*MEM/IO WRITE*/
`define PROC_MEMIO_WRITE 5'b10100
//`define PROC_MEMIO_WRITE_SETADDR 5'b10101
`define PROC_MEMIO_PUT_ALIGNED_DATA 5'b10101
`define PROC_MEMIO_PUT_UNALIGNED_DATA 5'b10110
`define PROC_MEMIO_PUT_BYTE 5'b10111
`define PROC_MEMIO_PUT_BYTE_STOP_READ 5'b11110 /****/
`define PROC_MEMIO_WRITE_EXIT 5'b11111 /****/
`define PROC_MEMIO_PUT_UNALIGNED_FIRST_BYTE 5'b00101 /****/
`define PROC_MEMIO_PUT_UNALIGNED_PREP_NEXT 5'b01100 /****/
`define PROC_MEMIO_PUT_UNALIGNED_PREP_NEXT1 5'b01101 /****/
`define PROC_MEMIO_PUT_UNALIGNED_PREP_NEXT2 5'b01110 /****/
`define PROC_MEMIO_PUT_UNALIGNED_PREP_NEXT3 5'b01111 /****/
`define PROC_MEMIO_PUT_UNALIGNED_PREP_NEXT4 5'b11010 /****/
`define PROC_MEMIO_WRITE 6'b101000
//`define PROC_MEMIO_WRITE_SETADDR 6'b010101
`define PROC_MEMIO_PUT_ALIGNED_DATA 6'b101001
`define PROC_MEMIO_PUT_UNALIGNED_DATA 6'b101010
`define PROC_MEMIO_PUT_BYTE 6'b101011
`define PROC_MEMIO_PUT_BYTE_STOP_READ 6'b101100
`define PROC_MEMIO_WRITE_EXIT 6'b101101
`define PROC_MEMIO_PUT_UNALIGNED_FIRST_BYTE 6'b101110
`define PROC_MEMIO_PUT_UNALIGNED_PREP_NEXT 6'b101111
`define PROC_MEMIO_PUT_UNALIGNED_PREP_NEXT1 6'b110001
`define PROC_MEMIO_PUT_UNALIGNED_PREP_NEXT2 6'b110010
`define PROC_MEMIO_PUT_UNALIGNED_PREP_NEXT3 6'b110011
`define PROC_MEMIO_PUT_UNALIGNED_PREP_NEXT4 6'b110100
`define PROC_NEXT_MICROCODE 6'b111000

178
system/processor.v
View File

@ -20,6 +20,7 @@
`include "proc_state_def.v"
`include "alu_header.v"
`include "config.v"
`include "ucode_header.v"
module processor ( input clock, input reset, output reg [19:0] external_address_bus, inout [15:0] external_data_bus,output reg read, output reg write, output reg HALT,output reg ERROR);
@ -31,63 +32,68 @@ assign external_data_bus=read?data_bus_output_register:16'hz;
reg [`PROC_STATE_BITS-1:0] state;
/* Decoder */
wire Wbit, Sbit, unaligning_instruction;
/*############ Decoder ########################################################## */
wire Wbit, Sbit, unaligning_instruction,opcode_size, has_operands;
wire [`PROC_STATE_BITS-1:0] next_state;
wire [1:0]MOD;
wire [2:0]RM;
wire [15:0]DE_PARAM1;
wire [15:0]DE_PARAM1;// Input param1 form decoder to alu
wire [15:0]DE_PARAM2;
wire DE_ERROR,DE_HALT;
wire [3:0]DE_reg_read_port1_addr,DE_reg_write_addr;
wire opcode_size;
wire has_operands;
wire [3:0]DE_reg_read_port1_addr,DE_reg_write_addr,DE_reg_read_port2_addr;
wire [11:0]DE_REGISTER_CONTROL;
wire [4:0]INSTRUCTION_INFO;
wire [1:0]DECODER_SIGNALS;
wire [`UCODE_ADDR_BITS-1:0] ucode_seq_addr_entry;
reg SIMPLE_MICRO; /* otuput simple decodings (=0) or microcode data (=1) */
decoder decoder(
CIR,FLAGS,Wbit,Sbit,unaligning_instruction,opcode_size,DE_ERROR,next_state
,MOD,RM,DE_PARAM1,DE_PARAM2,DE_HALT,has_operands
CIR,FLAGS,INSTRUCTION_INFO,DECODER_SIGNALS,next_state
,MOD,RM,DE_PARAM1,DE_PARAM2
,in_alu1_sel1,in_alu1_sel2,out_alu1_sel
,DE_reg_read_port1_addr,DE_reg_write_addr
,DE_REGISTER_CONTROL
,ALU_1OP
,ucode_seq_addr_entry,SIMPLE_MICRO,ucode_seq_addr
);
// Registers
reg [19:0] ProgCount; /*TODO consider having single circuit to increment PC instead of having possible lots of adders all over the code*/
assign Wbit=INSTRUCTION_INFO[4:4];
assign Sbit=INSTRUCTION_INFO[3:3];
assign unaligning_instruction=INSTRUCTION_INFO[2:2];
assign opcode_size=INSTRUCTION_INFO[1:1];
assign has_operands=INSTRUCTION_INFO[0:0];
assign DE_reg_write_addr=DE_REGISTER_CONTROL[11:8];
assign DE_reg_read_port1_addr=DE_REGISTER_CONTROL[7:4];
assign DE_reg_read_port2_addr=DE_REGISTER_CONTROL[3:0];
assign DE_HALT=DECODER_SIGNALS[0:0];
assign DE_ERROR=DECODER_SIGNALS[1:1];
reg [`UCODE_ADDR_BITS-1:0] ucode_seq_addr;
/*############ REGISTERS ########################################################## */
reg [19:0] ProgCount; //TODO: do i create a lot of adders each place i increment it?
reg [15:0] CIR;
reg [15:0] PARAM1;
reg [15:0] PARAM2;
reg one_byte_instruction;
reg unaligned_access;
reg we_jumped; /*Only used to signify that a microcoded instruction jumped and we should not update the unaligned_access bit after the end of the instruction*/
reg [15:0]FLAGS;
reg [15:0] BYTE_WRITE_TEMP_REG;//we read 16bits here if we want to change just 8 and leave the rest
/*** RESET LOGIC ***/
always @(negedge reset) begin
if (reset==0) begin
@(posedge clock);
state=`PROC_HALT_STATE;
ProgCount=0;//TODO: Reset Vector
HALT=0;
reg_write_we=1;
unaligned_access=0;
@(posedge reset)
@(negedge clock);
state=`PROC_IF_STATE_ENTRY;
one_byte_instruction=0;
ERROR=0;
end
end
/*** ALU and EXEC stage logic ***/
//Architectural Register file
reg [3:0] reg_write_addr;
wire [15:0] reg_write_data;
reg reg_write_we;
reg [3:0] reg_read_port1_addr;
reg [15:0] reg_read_port1_data;
reg [3:0] reg_read_port2_addr;
reg [15:0] reg_read_port2_data;
reg [1:0] reg_write_in_sel;
mux4 #(.WIDTH(16)) REG_FILE_WRITE_IN_MUX(
ALU_1O,
@ -96,9 +102,10 @@ mux4 #(.WIDTH(16)) REG_FILE_WRITE_IN_MUX(
16'hz,
reg_write_in_sel,
reg_write_data);
register_file register_file(reg_write_addr,reg_write_data,reg_write_we,reg_read_port1_addr,reg_read_port1_data);
register_file register_file(reg_write_addr,reg_write_data,reg_write_we,reg_read_port1_addr,reg_read_port1_data,reg_read_port2_addr,reg_read_port2_data);
/**** ALU 1 ******/
/*############ ALU / Execution units ########################################################## */
// ALU 1
reg [1:0] in_alu1_sel1;
reg [1:0] in_alu1_sel2;
/* out_alu1_sel : { EXTRA_FUNCTIONS_BIT[0:0], MOD_OR_EXTRA_FUNCTION[1:0] } */
@ -107,16 +114,16 @@ reg [2:0] out_alu1_sel;
mux4 #(.WIDTH(16)) MUX16_1A(
PARAM1,
reg_read_port1_data,
{ProgCount[14:0],unaligned_access},
16'b0,
{ProgCount[14:0],unaligned_access^unaligning_instruction},
16'b0000000000000000, /*0 Constant*/
in_alu1_sel1,
ALU_1A);
mux4 #(.WIDTH(16)) MUX16_1B(
PARAM2,
reg_read_port1_data,
{ProgCount[14:0],unaligned_access},
16'b0,
reg_read_port2_data,
{ProgCount[14:0],unaligned_access^unaligning_instruction},
16'b0000000000000001, /*1 Constant*/
in_alu1_sel2,
ALU_1B);
@ -127,6 +134,27 @@ reg [`ALU_OP_BITS-1:0]ALU_1OP;
wire [7:0] ALU_1FLAGS;
ALU ALU1(ALU_1A,ALU_1B,ALU_1O,ALU_1OP,ALU_1FLAGS,Wbit);
/*############ Processor state machine ########################################################## */
/*** RESET LOGIC ***/
always @(negedge reset) begin
if (reset==0) begin
@(posedge clock);
state=`PROC_HALT_STATE;
ucode_seq_addr=`UCODE_NO_INSTRUCTION;
ProgCount=0;//TODO: Reset Vector
HALT=0;
reg_write_we=1;
unaligned_access=0;
@(posedge reset)
@(negedge clock);
state=`PROC_IF_STATE_ENTRY;
one_byte_instruction=0;
ERROR=0;
SIMPLE_MICRO=0;
end
end
/*** Processor stages ***/
`define invalid_instruction state=`PROC_IF_STATE_ENTRY;ERROR=1;
@ -152,7 +180,11 @@ always @(negedge clock) begin
state=`PROC_DE_STATE_ENTRY;
end
`PROC_EX_STATE_EXIT:begin
unaligned_access=unaligning_instruction^unaligned_access;
/*Don't update the unaligned_access for Instruction
* Fetch if we are doing microcode execution, it will
* be done by decode at the end*/
if (ucode_seq_addr==`UCODE_NO_INSTRUCTION)
unaligned_access=unaligning_instruction^unaligned_access;
case(out_alu1_sel) /*TODO: use RM*/
3'b000,
3'b001,
@ -197,15 +229,31 @@ always @(negedge clock) begin
end
3'b011:begin
reg_write_we=0;
state=`PROC_IF_STATE_ENTRY;
if (ucode_seq_addr==`UCODE_NO_INSTRUCTION)
state=`PROC_IF_STATE_ENTRY;
else
state=`PROC_NEXT_MICROCODE;
end
3'b101:begin
3'b100:begin /*No output*/
if (ucode_seq_addr==`UCODE_NO_INSTRUCTION)
state=`PROC_IF_STATE_ENTRY;
else
state=`PROC_NEXT_MICROCODE;
end
3'b101:begin /* Program Counter*/
//if(SIMPLE_MICRO==1)
// ERROR=1;
ProgCount={5'b00000,ALU_1O[15:1]};
unaligned_access=ALU_1O[0:0];
state=`PROC_IF_STATE_ENTRY;
we_jumped=1;
if (ucode_seq_addr==`UCODE_NO_INSTRUCTION)
state=`PROC_IF_STATE_ENTRY;
else
state=`PROC_NEXT_MICROCODE;
end
3'b100:begin
state=`PROC_IF_STATE_ENTRY;
3'b110:begin /* Indirect write on SP */
reg_read_port1_addr=4'b1100;
state=`PROC_MEMIO_WRITE;
end
default:begin
`invalid_instruction
@ -226,7 +274,10 @@ always @(negedge clock) begin
end
`PROC_MEMIO_WRITE_EXIT:begin
write=0;
state=`PROC_IF_STATE_ENTRY;
if (ucode_seq_addr==`UCODE_NO_INSTRUCTION)
state=`PROC_IF_STATE_ENTRY;
else
state=`PROC_NEXT_MICROCODE;
end
`PROC_MEMIO_PUT_ALIGNED_DATA:begin
read=1;
@ -283,6 +334,7 @@ always @(posedge clock) begin
reg_write_we=1;
state=`PROC_IF_WRITE_CIR;
reg_write_in_sel=2'b00;
we_jumped=0;
end
`PROC_IF_STATE_EXTRA_FETCH_SET:begin
ProgCount=ProgCount+1;
@ -300,13 +352,28 @@ always @(posedge clock) begin
* external_data_bus contains at least some unknown data */
one_byte_instruction=(!has_operands)&&(!opcode_size);
external_address_bus = ProgCount;
state=next_state;
PARAM1=DE_PARAM1;
PARAM2=DE_PARAM2;
if(SIMPLE_MICRO==0)begin
/* We cannot set these directly within
* microcode so don't overwirte useful values
* each time the next microcode is executed.
* Note this still allows to set initial values
* at the start of the microcode */
PARAM1=DE_PARAM1;
PARAM2=DE_PARAM2;
end
ERROR=DE_ERROR;
HALT=DE_HALT;
reg_read_port1_addr=DE_reg_read_port1_addr;
reg_read_port2_addr=DE_reg_read_port2_addr;
reg_write_addr=DE_reg_write_addr;
if ( (ucode_seq_addr==`UCODE_NO_INSTRUCTION) && (ucode_seq_addr_entry!=`UCODE_NO_INSTRUCTION) )begin
/*switch to microcode decoding*/
ucode_seq_addr=ucode_seq_addr_entry;
SIMPLE_MICRO=1;
/*keep state the same and rerun decode this time with all the data from the microcode rom*/
end else begin
state=next_state;
end
end
`PROC_DE_LOAD_REG_TO_PARAM:begin
PARAM1=reg_read_port1_data;
@ -459,6 +526,21 @@ always @(posedge clock) begin
PARAM1[15:8]=external_data_bus[15:8];
state=`PROC_EX_STATE_ENTRY;
end
`PROC_NEXT_MICROCODE:begin
read=0;
write=1; // maybe we are coming from MEMIO_WRITE
ucode_seq_addr=ucode_seq_addr_entry; /*Reused for next address*/
if( ucode_seq_addr == `UCODE_NO_INSTRUCTION )begin
/*Finished microcode*/
if(we_jumped==0)
unaligned_access=unaligning_instruction^unaligned_access;
SIMPLE_MICRO=0;
state=`PROC_IF_STATE_ENTRY;
end else begin
state=`PROC_DE_STATE_ENTRY;
end
end
default:begin
end
endcase

10
system/registers.v
View File

@ -21,10 +21,13 @@
/* Register address format:
* [W-bit] [ 3-bit address] */
module register_file (write_port1_addr,write_port1_data,write_port1_we,read_port1_addr,read_port1_data);
input [3:0] write_port1_addr,read_port1_addr;
module register_file (write_port1_addr,write_port1_data,write_port1_we,read_port1_addr,read_port1_data,read_port2_addr,read_port2_data);
input [3:0] write_port1_addr;
input [3:0] read_port1_addr;
input [3:0] read_port2_addr;
input [15:0] write_port1_data;
output [15:0] read_port1_data;
output [15:0] read_port2_data;
input write_port1_we;
reg [15:0] registers [7:0];
@ -32,6 +35,9 @@ reg [15:0] registers [7:0];
assign read_port1_data = ( read_port1_addr[3:3] ? registers[read_port1_addr[2:0]] :
( read_port1_addr[2:2] ? {8'b0,registers[read_port1_addr[2:0]][15:8]} : {8'b0,registers[read_port1_addr[2:0]][7:0]} ) );
assign read_port2_data = ( read_port2_addr[3:3] ? registers[read_port2_addr[2:0]] :
( read_port2_addr[2:2] ? {8'b0,registers[read_port2_addr[2:0]][15:8]} : {8'b0,registers[read_port2_addr[2:0]][7:0]} ) );
`ifdef DEBUG_REG_WRITES
string debug_name;
`endif

9
system/ucode.hex
View File

@ -1,9 +0,0 @@
//s : Opcode size 0:8bit 1:16bit
//h : Has operands as part of the instruction: 0: No 1: Yes
// |sh
@000 01_11
@001 11_10
@002 1000
@003 0010

32
system/ucode.txt Normal file
View File

@ -0,0 +1,32 @@
//a1f: ALU 1 operation (function)
// 000:ALU_OP_ADD
// 001:ALU_OP_SUB
// 010:ALU_OP_AND
// 011:ALU_OP_OR
// 100:ALU_OP_XOR
// 101:ALU_OP_ADD_SIGNED_B
//
//a1o: out_alu1_sel. Handled in `PROC_EX_STATE_EXIT
//
//a12: In ALU 1 sel 2
//
//a11: In ALU 1 sel 1
//
//rwa: Register Write Address
//
//nxs: Next State
// 00: PROC_EX_STATE_ENTRY
// 01: PROC_DE_LOAD_16_PARAM
// 10: PROC_DE_LOAD_8_PARAM
// 11: PROC_DE_LOAD_REG_TO_PARAM
//
//Nxt M: Next microcode address
// 24 21 18 15 13 11 7 5 0
// rr1 |a1f|a1o|a12|a11|rwa |nxs|Nxt M |
@000 0000_000_000__00__00_0000__00_000000
@001 zzzz_000_110__10__11_0111__01_000010 // ALU_1: 0 ALU_2: PC ALU_OP:ADD ALU_out: [SP] (also fetch the opcode argument to PARAM1)
@002 1100_001_011__00__01_1100__00_000011 // ALU_1: SP ALU_2: PARAM2 (2) ALU_OP:SUB ALU_out: SP
@003 zzzz_000_101__10__00_zzzz__00_000000 // ALU_1: PARAM1 (arg) ALU_2: PC ALU_OP:ADD ALU_out: PC

7
system/ucode_header.v
View File

@ -1,6 +1,7 @@
`define UCODE_ADDR_BITS 9
`define UCODE_ADDR_BITS 5
`define UCODE_DATA_BITS 32
`define UCODE_SIZE 4
`define ADD_AL_IB 0
`define ADD_AX_IW 1
/* DEFINE ADDRESSES IN THE MICROCODE */
`define UCODE_NO_INSTRUCTION 5'b00000
`define UCODE_CALL_ENTRY 5'b00001