USRP Hardware Driver and USRP Manual  Version: 4.0.0.0-170-gd398fe465
UHD and USRP Manual
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_buffmemory to write the packed vrt header
if_packet_infothe 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_buffmemory to write the packed vrt header
if_packet_infothe 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_buffmemory to read the packed vrt header
if_packet_infothe 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_buffmemory to read the packed vrt header
if_packet_infothe if packet info (read/write)