Intel 8XC251SA SUB dest,src Function Subtract, SUB R1,R0, Variations SUB Rmd,Rms Binary Mode

INSTRUCTION SET REFERENCE

SRL WRj

Binary Mode Source Mode

Bytes:

States:

[Encoding]

Hex Code in:

Operation:

32

21

0 0 0 1 1 1 1 0

Binary Mode = [A5][Encoding] Source Mode = [Encoding]

SRL

(WRj).15 ← 0

(WRj).b ← (WRj).b+1 CY← (WRj).0

t t t t

0 1 0 0

SUB <dest>,<src>

Function: Subtract

Description: Subtracts the specified variable from the destination operand, leaving the result in the destination operand. SUB sets the CY (borrow) flag if a borrow is needed for bit 7. Otherwise, CY is clear.

When subtracting signed integers, the OV flag indicates a negative number produced when a negative value is subtracted from a positive value, or a positive result when a positive number is subtracted from a negative number.

Bit 7 in this description refers to the most significant byte of the operand (8, 16, or 32 bit).

The source operand allows four addressing modes: immediate, indirect, register and direct.

Flags:

CY	AC	OV	N	Z
✓	✓†	✓	✓	✓

†For word and dword subtractions, AC is not affected.

Example: Register 1 contains 0C9H (11001001B) and register 0 contains 54H (01010100B). After executing the instruction

SUB R1,R0

register 1 contains 75H (01110101B), the CY and AC flags are clear, and the OV flag is set.

Variations

SUB Rmd,Rms

	Binary Mode	Source Mode
Bytes:	3	2
States:	2	1

[Encoding]

1 0 0 1 1 1 0 0

s s s s S S S S

A-123