1. Documentation conventions
1.1 General information
The STM32F3xx devices have an Arm ®(a) Cortex ® -M4F core.
1.2 List of abbreviations for registers
The following abbreviations (b) are used in register descriptions:
| read/write (rw) | Software can read and write to this bit. |
| read-only (r) | Software can only read this bit. |
| write-only (w) | Software can only write to this bit. Reading this bit returns the reset value. |
| read/clear write0 (rc_w0) | Software can read as well as clear this bit by writing 0. Writing 1 has no effect on the bit value. |
| read/clear write1 (rc_w1) | Software can read as well as clear this bit by writing 1. Writing 0 has no effect on the bit value. |
| read/clear write (rc_w) | Software can read as well as clear this bit by writing to the register. The value written to this bit is not important. |
| read/clear by read (rc_r) | Software can read this bit. Reading this bit automatically clears it to 0. Writing this bit has no effect on the bit value. |
| read/set by read (rs_r) | Software can read this bit. Reading this bit automatically sets it to 1. Writing this bit has no effect on the bit value. |
| read/set (rs) | Software can read as well as set this bit. Writing 0 has no effect on the bit value. |
| read/write once (rwo) | Software can only write once to this bit and can also read it at any time. Only a reset can return the bit to its reset value. |
| toggle (t) | The software can toggle this bit by writing 1. Writing 0 has no effect. |
| read-only write trigger (rt_w1) | Software can read this bit. Writing 1 triggers an event but has no effect on the bit value. |
| Reserved (Res.) | Reserved bit, must be kept at reset value. |
1.3 Register reset value
Bits (binary notation) or bits nibbles (hexadecimal notation) of which the reset value is undefined are marked as X.
a. Arm is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere.
b. This is an exhaustive list of all abbreviations applicable to STMicroelectronics microcontrollers, some of them may not be used in the current document.
Bits (binary notation) or bits nibbles (hexadecimal notation) of which the reset value is unmodified are marked as U.
1.4 Glossary
This section gives a brief definition of acronyms and abbreviations used in this document:
- • Word : data of 32-bit length.
- • Half-word : data of 16-bit length.
- • Byte : data of 8-bit length.
- • IAP (in-application programming) : IAP is the ability to re-program the flash memory of a microcontroller while the user program is running.
- • ICP (in-circuit programming) : ICP is the ability to program the flash memory of a microcontroller using the JTAG protocol, the SWD protocol or the bootloader while the device is mounted on the user application board.
- • Option bytes : device configuration bits stored in the flash memory.
- • OBL : option byte loader.
- • AHB : advanced high-performance bus.
1.5 Availability of peripherals
For availability of peripherals and their number across all devices, refer to the particular device datasheet.