ST STM32H7 Series User Manual

PM0214 Rev 9 127/262
PM0214 The STM32 Cortex-M4 instruction set
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3.7.2 SSAT16 and USAT16
Signed Saturate and Unsigned Saturate to any bit position for two halfwords.
Syntax
op{cond} Rd, #n, Rm
Where:
• op’ is one of:
SSAT16 Saturates a signed halfword value to a signed range.
USAT16 Saturates a signed halfword value to an unsigned range.
• ‘cond’ is an optional condition code (see Conditional execution on page 65)
• ‘Rd’ is the destination register.
• ‘n’ specifies the bit position to saturate to:
n ranges from 1 to 16 for SSAT.
n ranges from 0 to 15 for USAT.
• ‘Rm’ is the register containing the value to saturate.
Operation
The SSAT16 instruction:
1. Saturates two signed 16-bit halfword values of the register with the value to saturate
from selected by the bit position in n.
2. Writes the results as two signed 16-bit halfwords to the destination register.
The USAT16 instruction:
1. Saturates two unsigned 16-bit halfword values of the register with the value to saturate
from selected by the bit position in n.
2. Writes the results as two unsigned halfwords in the destination register.
Restrictions
Do not use SP and do not use PC.
Condition flags
These instructions do not affect the condition code flags.
If saturation occurs, these instructions set the Q flag to 1.
Examples
SSAT16 R7, #9, R2 ; Saturates the top and bottom highwords of R2
; as 9-bit values, writes to corresponding halfword
; of R7
USAT16NE R0, #13, R5 ; Conditionally saturates the top and bottom
; halfwords of R5 as 13-bit values, writes to
; corresponding halfword of R0.

ST STM32H7 Series Specifications

General

Brand	ST
Model	STM32H7 Series
Category	Computer Hardware
Language	English

Summary

About this document

Typographical Conventions

Defines formatting used in the document for clarity.

List of Abbreviations for Registers

Provides a list of abbreviations used in register descriptions for quick reference.

STM32 Cortex-M4 Processor Overview

Introduces the STM32 Cortex-M4 processor's architecture and key features.

The Cortex-M4 Processor

Programmer's Model

Describes registers, modes, and privilege levels for software execution.

Memory Model

Details the processor's memory map, access behavior, and bit-banding features.

Exception Model

Explains exception states, types, priorities, and handling mechanisms.

Fault Handling

Covers fault types, escalation, status registers, and lockup conditions.

Power Management

Describes mechanisms for entering and exiting low-power sleep modes.

The STM32 Cortex-M4 Instruction Set

Instruction Set Summary

Lists supported Cortex-M4 instructions and their organization.

Memory Access Instructions

Details instructions for loading and storing data from/to memory.

General Data Processing Instructions

Explains instructions for arithmetic, logical, and data manipulation.

Multiply and Divide Instructions

Describes instructions for multiplication and division operations.

Floating-Point Instructions

Details instructions for FPU operations, including VFPv4-SP extension.

Miscellaneous Instructions

Covers instructions like breakpoints, barriers, and supervisor calls.

Core Peripherals

About the STM32 Cortex-M4 Core Peripherals

Introduces the core peripherals accessible via the Private Peripheral Bus (PPB).

Memory Protection Unit (MPU)

Explains the MPU for memory region definition and access control.

Nested Vectored Interrupt Controller (NVIC)

Describes the NVIC for managing interrupts and exceptions with priority levels.

System Control Block (SCB)

Details registers for system control, configuration, and exception reporting.

SysTick Timer (STK)

Explains the 24-bit SysTick timer for system timing and RTOS ticks.

Floating Point Unit (FPU)

Describes the FPU for single-precision floating-point operations.

Revision History