ST STM32H7 Series User Manual

PM0214 Rev 9 137/262
PM0214 The STM32 Cortex-M4 instruction set
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Examples
SXTH R4, R6, ROR #16 ; Rotates R6 right by 16 bits, obtains bottom halfword
; of result, sign extends to 32 bits and writes to R4
UXTB R3, R10 ; Extracts lowest byte of value in R10, zero extends, and
; writes to R3.
3.8.3 SXTA and UXTA
Signed and Unsigned Extend and Add
Syntax
op{cond} {Rd,} Rn, Rm {, ROR #n}
op{cond} {Rd,} Rn, Rm {, ROR #n}
Where:
• op’ is one of:
SXTAB Sign extends an 8-bit value to a 32-bit value and add.
SXTAH Sign extends a 16-bit value to a 32-bit value and add.
SXTAB16 Sign extends two 8-bit values to two 16-bit values and add.
UXTAB Zero extends an 8-bit value to a 32-bit value and add.
UXTAH Zero extends a 16-bit value to a 32-bit value and add.
UXTAB16 Zero extends two 8-bit values to two 16-bit values and add.
• ‘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 register holding the value to rotate and extend.
• ‘ROR #n’ is one of:
ROR #8 Value from Rm is rotated right 8 bits.
ROR #16 Value from Rm is rotated right 16 bits.
ROR #24 Value from Rm is rotated right 24 bits.
If ROR #n is omitted, no rotation is performed.
Operation
These instructions do the following:
1. Rotate the value from Rm right by 0, 8, 16 or 24 bits.
2. Extract bits from the resulting value:
SXTAB extracts bits[7:0] from Rm and sign extends to 32 bits.
UXTAB extracts bits[7:0] from Rm and zero extends to 32 bits.
SXTAH extracts bits[15:0] from Rm and sign extends to 32 bits.
UXTAH extracts bits[15:0] from Rm and zero extends to 32 bits.
SXTAB16 extracts bits[7:0] from Rm and sign extends to 16 bits,
and extracts bits [23:16] from Rm and sign extends to 16 bits.
UXTAB16 extracts bits[7:0] from Rm and zero extends to 16 bits,
and extracts bits [23:16] from Rm and zero extends to 16 bits.
3. Adds the signed or zero extended value to the word or corresponding halfword of Rn
and writes the result in Rd.

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