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CCR

  When the processor has completed the execution of an instruction, bits in the CCR are updated. The CCR flags are:

X	extend bit
N	negative
Z	zero
V	overflow
C	carry

Here are some examples of instructions affecting the CCR:

instruction	X	N	Z	V	C
ADD	affected	affected	affected	affected	affected
CMP	unaffected	affected	affected	affected	affected
MOVE	unaffected	affected	affected	cleared	cleared

The extend bit is affected by arithmetic instructions only, and is otherwise the same as the carry bit.

Table 2.2 in Clements provides a summary, and full information is given in the Motorola documentation.

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