ST STM32H7 Series User Manual

PM0214 Rev 9 107/262
PM0214 The STM32 Cortex-M4 instruction set
261
3.5.23 USADA8
Unsigned Sum of Absolute Differences and Accumulate
Syntax
USADA8{cond}{Rd,} Rn, Rm, Ra
Where:
• ‘cond’ is an optional condition code (see Conditional execution on page 65).
• ‘Rd’ is the destination register.
• ‘Rn’ is the first operand register.
• ‘Rm’ is the second operand register.
• ‘Ra’ is the register that contains the accumulation value.
Operation
The USADA8 instruction:
1. Subtracts each byte of the second operand register from the corresponding byte of the
first operand register.
2. Adds the unsigned absolute differences together.
3. Adds the accumulation value to the sum of the absolute differences.
4. Writes the result to the destination register.
Restrictions
Do not use SP and do not use PC.
Condition flags
These instructions do not change the flags.
Examples
USADA8 R1, R0, R6 ; Subtracts bytes in R0 from corresponding halfword of R1
; adds differences, adds value of R6, writes to R1
USADA8 R4, R0, R5, R2 ; Subtracts bytes of R5 from corresponding byte in R0
; adds differences, adds value of R2 writes to R4.

ST STM32H7 Series Specifications

General

Brand	ST
Model	STM32H7 Series
Category	Computer Hardware
Language	English