COM Helper Functions
[Communications Interface]

Functions
void	buf_insert16 (uint8_t *p, uint16_t pos, uint16_t word)
	Insert a uint16_t into an array of bytes in little endian byte order.
void	buf_insert32 (uint8_t *p, uint16_t pos, uint32_t dword)
	Insert a uint32_t into an array of bytes in little endian byte order.
uint16_t	buf_extract16 (uint8_t *p, uint16_t pos)
	Extracts a little endian uint16_t from an array of bytes.
uint32_t	buf_extract32 (uint8_t *p, uint16_t pos)
	Extracts a little endian uint32_t from an array of bytes.

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Detailed Description

These functions do not directly relate to the COM Layer, but are useful when dealing with comBufs on specific platforms.

Specifically, the buf_insert and buf_extract functions can be used instead of casting a byte pointer to a uint16_t* or uint32_t*. On some platforms such as the TELOSb, undefined behavior occurs if you read or write a 16-bit or 32-bit value to a location in memory that is not word aligned. These functions do not have such an issue.

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Function Documentation

uint16_t buf_extract16 (  uint8_t *  p, uint16_t  pos )

Parameters: p  A pointer to a byte array pos  The index from which to extract the uint16_t. Returns: the extracted 16-bit value.

uint32_t buf_extract32 (  uint8_t *  p, uint16_t  pos )

Parameters: p  A pointer to a byte array pos  The index from which to extract the uint32_t. Returns: the extracted 32-bit value.

void buf_insert16 (  uint8_t *  p, uint16_t  pos, uint16_t  word )

Parameters: p  A pointer to an array of uint8_ts.. pos  The index at which to insert the uint16_t. word  The 16-bit number to insert.

void buf_insert32 (  uint8_t *  p, uint16_t  pos, uint32_t  dword )

Parameters: p  A pointer to an array of uint8_ts. pos  The index at which to insert the uint32_t. dword  The 32-bit number to insert.

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