SAM47 INSTRUCTION SET

KS57C2308/P2308/C2316/P2316

 

 

XCHI — Exchange and Increment

XCHI Operation:

dst,src

Operand

Operation Summary

Bytes

Cycles

 

 

 

 

A,@HL

Exchange A and data memory contents; increment

1

2 + S

 

contents of register L and skip on overflow

 

 

 

 

 

 

Description: The instruction XCHI exchanges the contents of the accumulator with the RAM location addressed by register pair HL and then increments the contents of register L. If the content of register L is 0H, a skip is executed. The value of the carry flag is not affected.

Operand

 

 

Binary Code

 

 

Operation Notation

 

 

 

 

 

 

 

 

 

 

A,@HL

0

1

1

1

1

0

1

0

A (HL), then L L+1;

 

 

 

 

 

 

 

 

 

skip if L = 0H

 

 

 

 

 

 

 

 

 

 

Example: Register pair HL contains the address 2FH and internal RAM location 2FH contains 0FH:

 

LD

HL,#2FH

 

 

LD

A,#0H

 

 

XCHI

A,@HL

; A 0FH and L L + 1 = 0, (HL) "0"

 

JPS

XXX

; Skipped since an overflow occurred

 

JPS

YYY

; H 2H, L 0H

YYY

XCHI

A,@HL

; (20H) 0FH, A (20H), L L + 1 = 1H

 

 

 

 

 

 

 

 

 

The “JPS YYY” instruction is executed since a skip occurs after the XCHI instruction.

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Image 166
Samsung KS57C2308 manual Xchi Exchange and Increment, Xchi Operation, HL,#2FH, YYY Xchi @HL