68HC705JB2 datasheet(30/128 Pages) NXP

30 / 128 page

GENERAL RELEASE SPECIFICATION

August 28, 1998

CENTRAL PROCESSING UNIT

MC68HC705JB2

3-4

REV 1.1

The negative bit is set when the result of the last arithmetic operation, logical

operation, or data manipulation was negative. (Bit 7 of the result was a logical

one.)

The negative bit can also be used to check an often tested ﬂag by assigning the

ﬂag to bit 7 of a register or memory location. Loading the accumulator with the

contents of that register or location then sets or clears the negative bit according

to the state of the ﬂag.

3.6.4 Zero Bit (Z-Bit)

The zero bit is set when the result of the last arithmetic operation, logical

operation, data manipulation, or data load operation was zero.

3.6.5 Carry/Borrow Bit (C-Bit)

The carry/borrow bit is set when a carry out of bit 7 of the accumulator occurred

during the last arithmetic operation, logical operation, or data manipulation. The

carry/borrow bit is also set or cleared during bit test and branch instructions and

during shifts and rotates. This bit is neither set by an INC nor by a DEC instruction.

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

68HC705JB2 Datasheet(PDF) 30 Page - NXP Semiconductors