uhd::transport::vrt Namespace Reference

Namespaces
	chdr
	CHDR related function.

Classes
struct	if_packet_info_t

Functions
UHD_API void	if_hdr_pack_be (uint32_t *packet_buff, if_packet_info_t &if_packet_info)
UHD_API void	if_hdr_unpack_be (const uint32_t *packet_buff, if_packet_info_t &if_packet_info)
UHD_API void	if_hdr_pack_le (uint32_t *packet_buff, if_packet_info_t &if_packet_info)
UHD_API void	if_hdr_unpack_le (const uint32_t *packet_buff, if_packet_info_t &if_packet_info)

Function Documentation

if_hdr_pack_be()

UHD_API void uhd::transport::vrt::if_hdr_pack_be	(	uint32_t *	packet_buff,
		if_packet_info_t &	if_packet_info
	)

Pack a vrt header from metadata (big endian format).

Packing contract

Requirements:

• packet_buff points to a valid address space with enough space to write the entire buffer, regardless of its length. At the very least, it must be able to hold an entire header.
• if_packet_info has the following members set to correct values:
  • has_* members all set accordingly
  • For every true has_* member, the corresponding variable holds a valid value (e.g. if has_sid is true, sid contains a valid SID)
  • num_payload_bytes and num_payload_words32 are both set to the correct values

Result:

• packet_buff now points to a valid header that can be sent over the transport without further modification
• The following members on if_packet_info are set:
  • num_header_words32
  • num_packet_words32

Parameters

packet_buff	memory to write the packed vrt header
if_packet_info	the if packet info (read/write)

if_hdr_pack_le()

UHD_API void uhd::transport::vrt::if_hdr_pack_le	(	uint32_t *	packet_buff,
		if_packet_info_t &	if_packet_info
	)

Pack a vrt header from metadata (little endian format).

See Packing contract.

Parameters

packet_buff	memory to write the packed vrt header
if_packet_info	the if packet info (read/write)

if_hdr_unpack_be()

UHD_API void uhd::transport::vrt::if_hdr_unpack_be	(	const uint32_t *	packet_buff,
		if_packet_info_t &	if_packet_info
	)

Unpack a vrt header to metadata (big endian format).

Unpacking contract

Requirements

• packet_buff points to a readable address space with a CHDR packet, starting at the header. packet_buff[0] must always point to a valid first word of the header. This implies that num_packet_words32 must be at least 1.
• if_packet_info has the following members set to correct values:
  • num_packet_words32. This means all values packet_buff[0] through packet_buff[if_packet_info.num_packet_words32-1] are readable words from this packet.
  • link_type

Result

• if_packet_info now has the following values set to correct values:
  • packet_type
  • num_payload_bytes
  • num_payload_words32
  • num_header_words32
  • has_*
  • sob, eob, error, cid, sid (if applicable)
  • tsf, tsi (if applicable)

Exceptions

• If the header is invalid, but the requirements are still met, will throw a uhd::value_error.

Parameters

packet_buff	memory to read the packed vrt header
if_packet_info	the if packet info (read/write)

if_hdr_unpack_le()

UHD_API void uhd::transport::vrt::if_hdr_unpack_le	(	const uint32_t *	packet_buff,
		if_packet_info_t &	if_packet_info
	)

Unpack a vrt header to metadata (little endian format).

See Unpacking contract.

Parameters

packet_buff	memory to read the packed vrt header
if_packet_info	the if packet info (read/write)