From aaf69cb343e58328e5df5e118fa7d2e4f1321a14 Mon Sep 17 00:00:00 2001 From: Wade Fife Date: Wed, 9 Sep 2020 16:34:47 -0500 Subject: docs: Add new CHDR format to transports --- host/docs/vrt_chdr.dox | 30 +++++++++++++++++++++--------- 1 file changed, 21 insertions(+), 9 deletions(-) diff --git a/host/docs/vrt_chdr.dox b/host/docs/vrt_chdr.dox index 057294659..ae670a67d 100644 --- a/host/docs/vrt_chdr.dox +++ b/host/docs/vrt_chdr.dox @@ -6,20 +6,22 @@ Radio transport protocols are used to exchange samples (or other items) between If one were to sniff Ethernet traffic between a USRP and a PC, the packets would conform to a radio transport protocol. -For USRP devices, two radio transport protocols are relevant: VRT (the VITA Radio Transport protocol) -and CHDR (compressed header, an Ettus-specific protocol). -Generation-3 devices and the B200 use CHDR, the rest use VRT. +For USRP devices, three radio transport protocols are relevant: CHDR, Legacy +CHDR (from UHD 3.x) and VRT (the VITA Radio Transport protocol). -\section rtp_vrt VRT +All Generation-3 devices use CHDR. Prior to UHD 4.0, Generation-3 devices used +legacy CHDR. The B200 continues to use the legacy CHDR format. All other +Generation-1 and Generation-2 devices use VRT. -VRT is an open protocol defined by the VITA-49 standard. It was designed for interoperability, -and to allow different device types to work with different software stacks. -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 CHDR +The CHDR protocol is described in detail in the +[RFNoC Specification](https://files.ettus.com/app_notes/RFNoC_Specification.pdf). +Please refer to the specification document for protocol format information. -\section rtp_chdr CHDR + +\section rtp_legacy_chdr Legacy 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 @@ -66,6 +68,16 @@ Bit 63 | Bit 62 | Bit 61 | Bit 60 | Packet Type 1 | 1 | x | 0 | Command Response 1 | 1 | x | 1 | Command Response (Error) + +\section rtp_vrt VRT + +VRT is an open protocol defined by the VITA-49 standard. It was designed for interoperability, +and to allow different device types to work with different software stacks. + +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 vrt_tools Tools For CHDR, we provide a Wireshark dissector under tools/chdr_dissector. It can be used -- cgit v1.2.3