Техническая Спецификация для Atmel ARM-Based Evaluation Kit for SAM4S16C, 32-Bit ARM® Cortex® Microcontroller ATSAM4S-WPIR-RD ATSAM4S-WPIR-RD

SAM4S Series [DATASHEET]

Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14

126

REV16 Reverse byte order in each halfword independently.
REVSH Reverse byte order in the bottom halfword, and sign extend to 32 bits.
RBIT Reverse the bit order in a 32-bit word.
condis an optional condition code, see 

.

Rdis the destination register.
Rnis the register holding the operand.
Operation
Use these instructions to change endianness of data:
REV converts either:



32-bit big-endian data into little-endian data



32-bit little-endian data into big-endian data.

REV16 converts either:



16-bit big-endian data into little-endian data



16-bit little-endian data into big-endian data.

REVSH converts either:



16-bit signed big-endian data into 32-bit signed little-endian data



16-bit signed little-endian data into 32-bit signed big-endian data.

Restrictions
Do not use SP and do not use PC

Condition Flags
These instructions do not change the flags.
Examples

REV

R3, R7; Reverse byte order of value in R7 and write it to R3

REV16 R0, R0; Reverse byte order of each 16-bit halfword in R0

REVSH R0, R5; Reverse Signed Halfword

REVHS R3, R7; Reverse with Higher or Same condition

RBIT  R7, R8; Reverse bit order of value in R8 and write the result to R7.