Datasheet

Instruction Set Description

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4.6.3.7 BITX

BITX.A Test bits set in source address-word in destination address-word

BITX.[W] Test bits set in source word in destination word

BITX.B Test bits set in source byte in destination byte

BITX.A src,dst

Syntax

BITX src,dst or BITX.W src,dst

BITX.B src,dst

Operation src .and. dst → dst

Description The source operand and the destination operand are logically ANDed. The result affects

only the status bits. Both operands may be located in the full address space.

Status Bits N: Set if result is negative (MSB = 1), reset if positive (MSB = 0)

Z: Set if result is zero, reset otherwise

C: Set if the result is not zero, reset otherwise. C = (.not. Z)

V: Reset

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

Example Test if bit 16 or 15 of R5 (20-bit data) is set. Jump to label TONI if so.

BITX.A #018000h,R5 ; Test R5.16:15 bits

JNZ TONI ; At least one bit is set

... ; Both are reset

Example A table word pointed to by R5 (20-bit address) is used to test bits in R7. Jump to label

TONI if at least one bit is set.

BITX.W @R5,R7 ; Test bits in R7: C = .not.Z

JC TONI ; At least one is set

... ; Both are reset

Example A table byte pointed to by R5 (20-bit address) is used to test bits in input Port1. Jump to

label TONI if no bit is set. The next table byte is addressed.

BITX.B @R5+,&P1IN ; Test input P1 bits. R5 + 1

JNC TONI ; No corresponding input bit is set

... ; At least one bit is set

222

CPUX SLAU144J–December 2004–Revised July 2013

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