Computer Architecture Lab/WS2007/ZoWeAySi/Instruction Set II

Instruction Set II

Features

• 32-bit RISC processor
• Load/Store architecture
• Harvard architecture
• 32 32-bit general purpose registers
• 32-bit instruction width
• 4 pipeline stages
• memory mapped IO

Registers

GP Registers

Our Processor has 32 GP registers:

• $0 always zero
• $1..30 arbitrary
• $31 Stack Pointer

Flags

Our Processor features 4 flags in the flag register:

• CF .. Carry Flag
• SF .. Sign Flag
• ZF .. Zero Flag
• OF .. Overflow Flag

Instruction Encoding

Instruction Formats

R-Type:

Opcode	rt	rd	rs	cc	unused
6Bit	5Bit	5Bit	5Bit	4Bit	7Bit

I-Type:

Opcode	cc/rt	rd	immediate
6Bit	5Bit	5Bit	16Bit

Conditions (cc)

Encoding	Condition	cc	Description
0000	(unused)	none	unused at I-Type, LSB(rt) at R-Type
0001	$\mathrm{\neg }$ZF	NZ, NE	if ZF is not set, if not Equal
0010	$\mathrm{\neg }$SF	NS	if SF is not set
0011	$\mathrm{\neg }$OF	NO	if OF is not set
0100	$\mathrm{\neg }$CF	NC, AE	if CF is not set, if Above or Equal (unsigned)
0101	$\mathrm{\neg }$(CF $\vee$ ZF)	A	if Above (unsigned)
0110	$\mathrm{\neg }$(SF $\oplus$ OF)	GE	if Greater than or Equal (signed)
0111	$\mathrm{\neg }$((SF $\oplus$ OF) $\vee$ ZF)	GT	if Greater than (signed)
1000	true	none	true at I-Type, MSB(rt) at R-Type
1001	ZF	ZF, EQ	if ZF is set, if Equal
1010	SF	SF	if SF is set
1011	OF	OF	if OF is set
1100	CF	CF, B	if CF is set, if Below (unsigned)
1101	CF $\vee$ ZF	BE	if Below or Equal (unsigned)
1110	SF $\oplus$ OF	LT	if Less Than (signed)
1111	(SF $\oplus$ OF) $\vee$ ZF	LE	if Less than or Equal (signed)

Processor Instructions

R-Type

Instruction	Semantics	Flags	Opcode	rt	rd	rs	cc	Description
ADD rd rs rt	rd := rs + rt	ZF, SF, OF, CF	000000	rt	rd	rs	0000	Add
SUB rd rs rt	rd := rs - rt	ZF, SF, OF, CF	000001	rt	rd	rs	0000	Subtract
ADC rd rs rt	rd := rs + rt + CF	ZF, SF, OF, CF	000010	rt	rd	rs	0000	Add with carry
SBB rd rs rt	rd := rs - rt - CF	ZF, SF, OF, CF	000011	rt	rd	rs	0000	Subtract with borrow
INSccL rd rs	rd := (rs<<1)+ cc	ZF, SF, OF, CF	000100	rs	rd	rs	cc	Insert condition low
INSLL rd rs rt	rd := (rs<<1)+ LSB(rt)	ZF, SF, OF, CF	000100	rt	rd	rs	0000	Insert LSB low
INSML rd rs rt	rd := (rs<<1)+ MSB(rt)	ZF, SF, OF, CF	000100	rt	rd	rs	1000	Insert MSB low
INSccH rd rs	rd := (rs>>1)+cc*2^31	ZF, SF, OF, CF	000110	$0	rd	rs	cc	Insert condition high
INSLH rd rs rt	rd := (rs>>1)+LSB(rt)2^31	ZF, SF, OF, CF	000110	rt	rd	rs	0000	Insert LSB high
INSMH rd rs rt	rd := (rs>>1)+MSB(rt)2^31	ZF, SF, OF, CF	000110	rt	rd	rs	1000	Insert MSB high
AND rd rs rt	rd := rs $\wedge$ rt	ZF, SF	001000	rt	rd	rs	0000	And
ANDN rd rs rt	rd := rs $\wedge$ $\mathrm{\neg }$rt	ZF, SF	001001	rt	rd	rs	0000	And Not
XOR rd rs rt	rd := rs $\oplus$ rt	ZF, SF	001010	rt	rd	rs	0000	Xor
XORN rd rs rt	rd := rs $\oplus$ $\mathrm{\neg }$rt	ZF, SF	001011	rt	rd	rs	0000	Xor Not
OR rd rs rt	rd := rs $\vee$ rt	ZF, SF	001100	rt	rd	rs	0000	Or
ORN rd rs rt	rd := rs $\vee$ $\mathrm{\neg }$rt	ZF, SF	001101	rt	rd	rs	0000	Or Not
LD rd rt	rd := [rt]	none	010000	rt	rd	$0	0000	Load from Address
ST rt rs	[rt] := rs	none	010010	rt	$0	rs	0000	Store to Address
MOVcc rd rs rt	rd := (cc)? rs: rt	none	010100	rt	rd	rs	cc	Move on Condition
JMP rs	pc := rs	none	011100	01000	$0	rs	0000	Jump indirect
Jcc rs	pc := (cc)? rs: pc+4	none	011100	cc	$0	rs	0000	Jump indirect if cc
JSR rs	[sp]:=pc+4; pc:=rs	none	011110	sp	$0	rs	0000	Jump to Subroutine indirect

I-Type

Instruction	Semantics	Flags	Opcode	rt/cc	rd	imm	Description
IADD rd imm rt	rd := imm + rt	ZF, SF, OF, CF	100000	rt	rd	imm	Immediate Add
ISUB rd imm rt	rd := imm - rt	ZF, SF, OF, CF	100001	rt	rd	imm	Immediate Subtract
IADC rd imm rt	rd := imm + rt + CF	ZF, SF, OF, CF	100010	rt	rd	imm	Immediate Add with carry
ISBB rd imm rt	rd := imm - rt - CF	ZF, SF, OF, CF	100011	rt	rd	imm	Immediate Subtract with borrow
IAND rd imm rt	rd := imm $\wedge$ rt	ZF, SF	101000	rt	rd	imm	Immediate And
IANDN rd imm rt	rd := imm $\wedge$ $\mathrm{\neg }$rt	ZF, SF	101001	rt	rd	imm	Immediate And Not
IXOR rd imm rt	rd := imm $\oplus$ rt	ZF, SF	101010	rt	rd	imm	Immediate Xor
IXORN rd imm rt	rd := imm $\oplus$ $\mathrm{\neg }$rt	ZF, SF	101011	rt	rd	imm	Immediate Xor Not
IOR rd imm rt	rd := imm $\vee$ rt	ZF, SF	101100	rt	rd	imm	Immediate Or
IORN rd imm rt	rd := imm $\vee$ $\mathrm{\neg }$rt	ZF, SF	101101	rt	rd	imm	Immediate Or Not
LDI rd imm	rd := [imm]	none	110000	$0	rd	imm	Load from immediate Address
STI imm rt	[imm] := rt	none	110010	rt	$0	imm	Store to immediate Address
INSI rd imm rt	rd := imm + (rt << 16)	none	110100	rt	rd	imm	Insert immediate into register
INSIN rd imm rt	rd := imm + (~rt << 16)	none	110101	rt	rd	imm	Insert immediate into negated register
RET imm	pc := [sp]; sp += imm	none	111000	sp	sp	imm	Return (and clean up stack)
JMP label	pc := label	none	111100	01000	$0	label	Jump to target address
JMPcc label	pc := (cc)? label: pc+4	none	111100	cc	$0	label	Jump to target address if cc
JSR label	[sp]:=pc+4; pc:=label	none	111110	sp	$0	label	Jump to Subroutine

Instruction Mappings

Instruction	Semantics	Flags	Mapping
CMP rs rt	rs - rt	ZF, SF, OF, CF	SUB $0 rs rt
CMPI rt imm	rt - imm	ZF, SF, OF, CF	IADD $0 -imm rt
ICMP imm rt	imm - rt	ZF, SF, OF, CF	ISUB $0 imm rt
MOV rd rs	rd := rs	none	MOVCF rd rs rs
NEG rd rt	rd := -rt	ZF, SF, OF, CF	SUB rd $0 rt
NOP		none	MOVCF $1, $1, $1
NOT rd rs	rd := $\mathrm{\neg }$rs	ZF, SF	XORN rd rs $0
RCL rd rs		ZF, SF, OF, CF	ADC rd rs rs
RCR rd rs		ZF, SF, OF, CF	INSCFH rd rs
RET	pc := [sp]; sp += 4;	none	RET 4
ROL rd rs		ZF, SF, OF, CF	INSML rd rs rs
ROR rd rs		ZF, SF, OF, CF	INSLH rd rs rs
SAR rd rs	rd := rs >>> 1	ZF, SF, OF, CF	INSMH rd rs rs
SETcc rd	rd := (cc)? 1: 0	ZF, SF, OF, CF	INSccL rd $0
SHL rd rs	rd := rs << 1	ZF, SF, OF, CF	ADD rd rs rs
SHR rd rs	rd := rs >> 1	ZF, SF, OF, CF	INSMH rd rs $0
SUBI rd rt imm	rd := rs - imm	ZF, SF, OF, CF	IADD rd -imm rt