Difference between revisions of "Synchronizing USRP Events Using Timed Commands in UHD"
From Ettus Knowledge Base
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| + | The type of packet is determined by the state of bits 63 and 62 in the CHDR header. See [https://files.ettus.com/manual/page_rtp.html UHD Manual: Radio Transport Protocols] for more information on CHDR structure. | ||
===VITA Time=== | ===VITA Time=== | ||
Revision as of 16:18, 4 February 2020
Contents
Application Note Number
AN-TC
Revision History
| Date | Author | Details |
|---|---|---|
| 2020-02-10 | Sam Reiter | Initial creation |
Abstract
This AN discusses Timed Commands in UHD. We will explore usecases, theory of operation, and examples of timed command use in UHD 3.x.
Timed Commands: Overview and Usecases
- A
- B
- C
- D
- E
- F
- G
Clocking and Timekeeping in the USRP
CHDR Packet Types and Structure
CHDR or "Compressed Header" packets are a derivative of the VITA 49 (VRT) protocol. While the CHDR protocol is proprietary to USRP devices, mapping to and from VITA-49 is a trivial task. All packet routing in b2xx and "Gen 3" USRPs uses the CHDR protocol.
There are 4 types of packets used in the USRP:
- Data
- Flow Control
- Command
- Command Response
The type of packet is determined by the state of bits 63 and 62 in the CHDR header. See UHD Manual: Radio Transport Protocols for more information on CHDR structure.
