Tau CPU Worksheet

	A	B	C	D	G	H	I	J
1		Description	Mnemotic	Special Argument	Instruction	Formatting/syntax		General CPU Specifications
2	2-operand Instructions				2-operand	XXXX + DD + SS		8 bit CPU, 10 tick clock
3	0000	Addition	ADD	No		X: Operation code (from 0000 to 1010)		2-operand architecture
4	0001	Subtraction	SUB	No		DD: Destination register (and source 1)		256 B data memory (64B cached)
5	0010	Logical XOR	XOR	No		SS: Source 2 register		1024 B program memory (64B cached)
6	0011	Logical AND	AND	No		No argument possible		Static branch prediction (not taken)
7	0100	Logical OR	OR	No	Example: 0001 01 11	R1 = R1-R3		7 registers (banked)
8	0101	Compare	CMP	No				3 stage F-D-E pipeline
9	0110	Copy	CPY	No	1-operand	1100 + DD + OO		4 I/O ports
10	0111	Add with carry	ADC	No		DD: Destination register (and source)		8-deep callstack
11	1000	Memory Load	MLD	No		OO: Operation code (from 00 to 11)		3 ALU flags (zero, neg, carry)
12	1001	Memory Store	MST	No		No argument possible		8-bit fixed instruction length
13	1010	Port Load	PLD	No	Example: 1100 10 10	Increment R2
14	1011	Port Store	PST	No
15					Immediate	1101 + DD + OO + IIIIIIII
16	1-operand Instructions (1100)					DD: Destination register (and source)
17	00	Right shift	RSH	No		OO: Operation code (from 00 to 11)
18	01	Invert register	INV	No		I: 8-bit immediate given in argument
19	10	Increment	INC	No	Example: 1101 01 10 00000101	R1 = R1 - 5
20	11	Decrement	DEC	No
21					Branching	1110 + II + OO + IIIIIIII
22	Immediate Instructions (1101)					OO: Operation code (from 00 to 01)
23	00	Load immediate	LDI	8-bit immediate		I: 10-bit immediate, in arg. and first byte
24	01	Add immediate	ADI	8-bit immediate	Example: 1110 01 01 00100110	Call address 294
25	10	Compare immediate	CPI	8-bit immediate
26	11	And immediate	ANI	8-bit immediate	Implicit	1111 + OOOO
27						OOOO: Operation code (from 0000 to 1111)
28	Branching Instructions (1110)					No argument possible
29	00	Jump	JMP	10-bit immediate	Example: 1111 0111	Skip next 2 instructions if negative
30	01	Call	CAL	10-bit immediate
31					Skips	1111 + 1FFF
32	Implicit Instructions (1111)					FFF: Flags (combineable)
33	0000	Bank left	BKL	No	Skip flags	Description	Argument
34	0001	Bank right	BKR	No	000	Skip never	!
35	0010	Halt	HLT	No	001	Skip if zero	0
36	0011	Return	RET	No	010	Skip if not zero	!0
37	1xxx	Skip	SKP	No	011	Skip if negative	-
38					100	Skip if not negative	!-
39					101	Skip always	None
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