PM0223 datasheet(64/110 Pages) STMICROELECTRONICS

部件名	PM0223

功能描述	This programming manual provides information for application and system-level software developers

PDF	110 Pages

Scroll/Zoom	100%

制造商	STMICROELECTRONICS [STMicroelectronics]

网页	http://www.st.com

标志

64 / 110 page

The STM32L0 Cortex-M0+ Instruction Set

PM0223

64/110

DocID025763 Rev 1

3.5.9

TST

Test bits.

Syntax

TST Rn, Rm

where:

Operation

This instruction tests the value in a register against another register. It updates the condition

flags based on the result, but does not write the result to a register.

The TST instruction performs a bitwise AND operation on the value in Rn and the value in

. This is the same as the ANDS instruction, except that it discards the result.

To test whether a bit of Rn is 0 or 1, use the TST instruction with a register that has that bit

set to 1 and all other bits cleared to 0.

Restrictions

In these instructions, Rn and Rm must only specify R0-R7.

Condition flags

This instruction:

•

updates the N and Z flags according to the result

•

does not affect the C or V flags.

Examples

TST

R0, R1 ; Perform bitwise AND of R0 value and R1 value,

; condition code flags are updated but result is discarded

Is the register holding the first operand.

The register to test against.

PM0223 数据表(PDF) 64 Page - STMicroelectronics