bit.h File Reference

Bit access macros for Cortex-M based CPUs. More...

Detailed Description

Bit access macros for Cortex-M based CPUs.

Author

Joakim Nohlgård joaki.nosp@m.m.no.nosp@m.hlgar.nosp@m.d@ei.nosp@m.stec..nosp@m.se

Definition in file bit.h.

#include <stdint.h>
#include "cpu.h"

Include dependency graph for bit.h:

Go to the source code of this file.

#define	CPU_HAS_BITBAND   1 || 0 (1 for Cortex-M3 and up, 0 for Cortex-M0)
	Flag for telling if the CPU has hardware bit band support.

Bit manipulation functions
static volatile void *	bitband_addr (volatile void *ptr, uintptr_t bit)
	Convert bit band region address and bit number to bit band alias address. More...
static void	bit_set32 (volatile uint32_t *ptr, uint8_t bit)
	Set a single bit in the 32 bit word pointed to by ptr. More...
static void	bit_set16 (volatile uint16_t *ptr, uint8_t bit)
	Set a single bit in the 16 bit word pointed to by ptr. More...
static void	bit_set8 (volatile uint8_t *ptr, uint8_t bit)
	Set a single bit in the 8 bit byte pointed to by ptr. More...
static void	bit_clear32 (volatile uint32_t *ptr, uint8_t bit)
	Clear a single bit in the 32 bit word pointed to by ptr. More...
static void	bit_clear16 (volatile uint16_t *ptr, uint8_t bit)
	Clear a single bit in the 16 bit word pointed to by ptr. More...
static void	bit_clear8 (volatile uint8_t *ptr, uint8_t bit)
	Clear a single bit in the 8 bit byte pointed to by ptr. More...

Function Documentation

bit_clear16()

static void bit_clear16 ( volatile uint16_t *  ptr, uint8_t  bit  )

inlinestatic

Clear a single bit in the 16 bit word pointed to by ptr.

The effect is the same as for the following snippet:

*ptr &= ~(1 << bit);

There is a read-modify-write cycle occurring within the core, but this cycle is atomic and can not be disrupted by IRQs

Parameters

[in]	ptr	pointer to target word
[in]	bit	bit number within the word

Definition at line 163 of file bit.h.

bit_clear32()

static void bit_clear32 ( volatile uint32_t *  ptr, uint8_t  bit  )

inlinestatic

Clear a single bit in the 32 bit word pointed to by ptr.

The effect is the same as for the following snippet:

*ptr &= ~(1 << bit);

There is a read-modify-write cycle occurring within the core, but this cycle is atomic and can not be disrupted by IRQs

Parameters

[in]	ptr	pointer to target word
[in]	bit	bit number within the word

Definition at line 143 of file bit.h.

bit_clear8()

static void bit_clear8 ( volatile uint8_t *  ptr, uint8_t  bit  )

inlinestatic

Clear a single bit in the 8 bit byte pointed to by ptr.

The effect is the same as for the following snippet:

*ptr &= ~(1 << bit);

There is a read-modify-write cycle occurring within the core, but this cycle is atomic and can not be disrupted by IRQs

Parameters

[in]	ptr	pointer to target byte
[in]	bit	bit number within the byte

Definition at line 183 of file bit.h.

bit_set16()

static void bit_set16 ( volatile uint16_t *  ptr, uint8_t  bit  )

inlinestatic

Set a single bit in the 16 bit word pointed to by ptr.

The effect is the same as for the following snippet:

*ptr |= (1 << bit);

There is a read-modify-write cycle occurring within the core, but this cycle is atomic and can not be disrupted by IRQs

Parameters

[in]	ptr	pointer to target word
[in]	bit	bit number within the word

Definition at line 103 of file bit.h.

bit_set32()

static void bit_set32 ( volatile uint32_t *  ptr, uint8_t  bit  )

inlinestatic

Set a single bit in the 32 bit word pointed to by ptr.

The effect is the same as for the following snippet:

*ptr |= (1 << bit);

There is a read-modify-write cycle occurring within the core, but this cycle is atomic and can not be disrupted by IRQs

Parameters

[in]	ptr	pointer to target word
[in]	bit	bit number within the word

Definition at line 83 of file bit.h.

bit_set8()

static void bit_set8 ( volatile uint8_t *  ptr, uint8_t  bit  )

inlinestatic

Set a single bit in the 8 bit byte pointed to by ptr.

The effect is the same as for the following snippet:

*ptr |= (1 << bit);

There is a read-modify-write cycle occurring within the core, but this cycle is atomic and can not be disrupted by IRQs

Parameters

[in]	ptr	pointer to target byte
[in]	bit	bit number within the byte

Definition at line 123 of file bit.h.

bitband_addr()

static volatile void* bitband_addr ( volatile void *  ptr, uintptr_t  bit  )

inlinestatic

Convert bit band region address and bit number to bit band alias address.

Parameters

[in]	ptr	base address in non bit banded memory
[in]	bit	bit number within the word

Returns

Address of the bit within the bit band memory region

Definition at line 62 of file bit.h.