PM0056 datasheet(17/156 Pages) STMICROELECTRONICS

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PM0056

The Cortex-M3 processor

Application program status register

The APSR contains the current state of the condition flags from previous instruction

executions. See the register summary in Table 2 on page 14 for its attributes. The bit

assignments are:

Table 4. APSR bit definitions

Bits

Description

Bit 31

N: Negative or less than flag:

0: Operation result was positive, zero, greater than, or equal

1: Operation result was negative or less than.

Bit 30

Z: Zero flag:

0: Operation result was not zero

1: Operation result was zero.

Bit 29

C: Carry or borrow flag:

0: Add operation did not result in a carry bit or subtract operation resulted in a

borrow bit

1: Add operation resulted in a carry bit or subtract operation did not result in a

borrow bit.

Bit 28

V: Overflow flag:

0: Operation did not result in an overflow

1: Operation resulted in an overflow.

Bit 27

Q: Sticky saturation flag:

0: Indicates that saturation has not occurred since reset or since the bit was last

cleared to zero

1: Indicates when an SSAT or USAT instruction results in saturation.

This bit is cleared to zero by software using an MRS instruction.

Bits 26:0

Reserved.

PM0056 Datasheet(PDF) 17 Page - STMicroelectronics