Datasheet

15 8 7 0

Instruction Set

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3.4.6.49 SXT

SXT Extend Sign

Syntax SXT dst

Operation Bit 7 → Bit 8 ......... Bit 15

Description The sign of the low byte is extended into the high byte as shown in Figure 3-20.

Status Bits N: Set if result is negative, reset if positive

Z: Set if result is zero, reset otherwise

C: Set if result is not zero, reset otherwise (.NOT. Zero)

V: Reset

Mode Bits OSCOFF, CPUOFF, and GIE are not affected.

Figure 3-20. Destination Operand - Sign Extension

Example R7 is loaded with the P1IN value. The operation of the sign-extend instruction expands

bit 8 to bit 15 with the value of bit 7.

R7 is then added to R6.

MOV.B &P1IN,R7 ; P1IN = 080h: .... .... 1000 0000

SXT R7 ; R7 = 0FF80h: 1111 1111 1000 0000

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CPU SLAU144J–December 2004–Revised July 2013

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