diff options
| -rw-r--r-- | host/docs/vrt_chdr.dox | 15 | ||||
| -rw-r--r-- | host/include/uhd/transport/chdr.hpp | 6 | ||||
| -rw-r--r-- | host/include/uhd/transport/vrt_if_packet.hpp | 2 | ||||
| -rw-r--r-- | host/lib/usrp/device3/device3_io_impl.cpp | 2 |
4 files changed, 12 insertions, 13 deletions
diff --git a/host/docs/vrt_chdr.dox b/host/docs/vrt_chdr.dox index 560f0b6a3..a2d36c93e 100644 --- a/host/docs/vrt_chdr.dox +++ b/host/docs/vrt_chdr.dox @@ -7,8 +7,8 @@ If one were to sniff Ethernet traffic between a USRP and a PC, the packets would radio transport protocol. For USRP devices, two radio transport protocols are relevant: VRT (the VITA Radio Transport protocol) -and CVITA (compressed VITA), also known as CHDR. Generation-3 devices and the B200 use CHDR, the rest -use VRT. +and CHDR (compressed header, an Ettus-specific protocol). +Generation-3 devices and the B200 use CHDR, the rest use VRT. \section rtp_vrt VRT @@ -19,13 +19,12 @@ VRT is a very verbose standard, and only a subset is implemented in UHD/USRPs. The full standard is available from the VITA website: http://www.vita.com . -\section rtp_chdr CVITA (CHDR) +\section rtp_chdr CHDR For the third generation of Ettus devices, a new type transport protocol was designed. It reduces the complexity of the original standard and uses a fixed-length 64-Bit header -for everything except the timestamp. Because this is a "compressed" form of VITA, it -was dubbed "Compressed VITA" (CVITA). The compressed header is called CHDR, which is why -the protocol is often called CHDR itself (pronounced like the cheese "cheddar"). +for everything except the timestamp. Because it is "compressed" into a 64-bit heaer, it +was dubbed CHDR (pronounced like the cheese "cheddar"). By compressing all information into a 64-bit line, the header can efficiently be parsed in newer FPGAs, where the common streaming protocol is 64-Bit AXI. The first line in a @@ -33,7 +32,7 @@ packet already provides all necessary information to proceed. Some CHDR-specific functions can be found in: uhd::transport::vrt::chdr. -The form of a CVITA packet is the following: +The form of a CHDR packet is the following: Address (Bytes) | Length (Bytes) | Payload ----------------|----------------|---------------------------- @@ -76,7 +75,7 @@ for Ethernet links as well as USB (e.g., for the B210). Relevant code sections for the radio transport layer are: * uhd::transport::vrt - Namespace for radio transport protocol related functions and definitions -* uhd::transport::vrt::chdr - Sub-namespace specifically for CVITA/CHDR +* uhd::transport::vrt::chdr - Sub-namespace specifically for CHDR * uhd::sid_t - Datatype to represent SIDs */ diff --git a/host/include/uhd/transport/chdr.hpp b/host/include/uhd/transport/chdr.hpp index fa2ae074e..3c85056d7 100644 --- a/host/include/uhd/transport/chdr.hpp +++ b/host/include/uhd/transport/chdr.hpp @@ -22,9 +22,9 @@ namespace uhd{ namespace transport{ namespace vrt{ -/*! \brief CVITA/CHDR related function +/*! \brief CHDR related function * - * See \ref rtp_chdr for details on the CVITA/CHDR protocol. + * See \ref rtp_chdr for details on the CHDR protocol. * * All packers take the host format into account. Choose the _le functions * if the transport uses little endian format (e.g. PCIe) and the _be @@ -46,7 +46,7 @@ namespace uhd{ namespace transport{ namespace vrt{ */ namespace chdr{ - //! The maximum number of 64-bit words in a CVITA header + //! The maximum number of 64-bit words in a CHDR header static const size_t max_if_hdr_words64 = 2; // CHDR + tsf (fractional timestamp) /*! diff --git a/host/include/uhd/transport/vrt_if_packet.hpp b/host/include/uhd/transport/vrt_if_packet.hpp index 7d0123c42..1e0f4b2e0 100644 --- a/host/include/uhd/transport/vrt_if_packet.hpp +++ b/host/include/uhd/transport/vrt_if_packet.hpp @@ -57,7 +57,7 @@ namespace vrt{ PACKET_TYPE_IF_EXT = 0x1, PACKET_TYPE_CONTEXT = 0x2, //extension context: has_sid = true - // CVITA language: + // CHDR language: //PACKET_TYPE_DATA = 0x0, // Data PACKET_TYPE_FC = 0x1, // Flow control PACKET_TYPE_ACK = 0x1, // Flow control (ack) diff --git a/host/lib/usrp/device3/device3_io_impl.cpp b/host/lib/usrp/device3/device3_io_impl.cpp index b4aac71bf..ea6bedb74 100644 --- a/host/lib/usrp/device3/device3_io_impl.cpp +++ b/host/lib/usrp/device3/device3_io_impl.cpp @@ -38,7 +38,7 @@ using namespace uhd; using namespace uhd::usrp; using namespace uhd::transport; -//! CVITA uses 12-Bit sequence numbers +//! CHDR uses 12-Bit sequence numbers static const uint32_t HW_SEQ_NUM_MASK = 0xfff; |