Difference between revisions of "Protocol decoder:Cec"

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(Created page with "{{Infobox protocol decoder | id = cec | name = cec | description = HDMI Consumer Electronics Control (CEC) protocol. | status = supported...")
 
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| license        = GPLv2+
| license        = GPLv2+
| source_code_dir = cec
| source_code_dir = cec
| image          = [[File:|250px]]
| image          = [[File:Cec_hdmi_pinout.png|250px]]
| input          = logic
| input          = logic
| output          = cec
| output          = cec
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== HDMI CEC protocol decoder ==


Sigrok protocol decoder for HDMI CEC (Consumer Electronics Control)
Consumer Electronics Control (CEC) is a feature of HDMI designed to allow users to command and control devices connected through HDMI


Consumer Electronics Control (CEC) is a feature of HDMI designed to allow users to command and control devices connected through HDMI
== Hardware ==


CEC Bus can be found in PIN 13 of the HDMI connector:
CEC Bus can be found in PIN 13 of the HDMI connector:
[[File:Cec_hdmi_pinout.png]]
== Protocol ==
It is a one-wire bidirectional serial bus that is based on the [https://en.wikipedia.org/wiki/European_Committee_for_Electrotechnical_Standardization CENELEC] standard AV.link protocol to perform remote control functions.
CEC is a separate electrical signal from the other HDMI signals. This allows a device to disable its high-speed HDMI circuitry in sleep mode, but be woken up by CEC. It is a single shared bus, which is directly connected between all HDMI ports on a device, so it can flow through a device which is completely powered off (not just asleep).
The bus is electrically identical to the AV.link protocol, but CEC adds a detailed higher-level message protocol.
The bus is an open-collector line, somewhat like I²C, passively pulled up to +3.3 V, and driven low to transmit a bit.
== Pulseview screenshots ==
<gallery widths=800px>
File:Cec_pulseview_ping_frames.png|<small>Ping (poll) frames</small>
File:cec_pulseview_vendor_command_frame.png|<small>Vendor command frame</small>
</gallery>
== Usage examples ==
'''Print all annotations (very verbose)'''
  '''sigrok-cli -i data.sr -P cec:CEC=CEC'''
 
  cec-1: ST
  cec-1: 0
  cec-1: 0
  cec-1: 1
  cec-1: 1
  cec-1: 0
  cec-1: 0
  cec-1: 0
  cec-1: 0
  cec-1: 0x30
  cec-1: EOM=N
  cec-1: ACK
  cec-1: 0
  cec-1: 0
  cec-1: 0
  cec-1: 0
  cec-1: 0
  cec-1: 1
  cec-1: 0
  cec-1: 0
  cec-1: 0x04
  cec-1: EOM=Y
  cec-1: ACK
  cec-1: 30:04
  cec-1: HDR: Tuner_1, TV | OPC: IMAGE_VIEW_ON | R: ACK
'''Print frames only'''
  '''sigrok-cli -i data.sr -P cec:CEC=CEC -A cec=frames'''
  cec-1: 30:04
  cec-1: 35
  cec-1: 35
  cec-1: 3f:82:10:00
  cec-1: 30:8f
  cec-1: 03:90:01
  cec-1: 30:44:6d
  cec-1: 35
  cec-1: 35
  cec-1: 30:04
  cec-1: 35
  cec-1: 35
  cec-1: 30:0d
  cec-1: 35
  cec-1: 35
  cec-1: 35
  cec-1: 35
  cec-1: 30:04
  cec-1: 35
  cec-1: 35
  cec-1: 30:8f
  cec-1: 03:90:01
  cec-1: 35
  cec-1: 35
  cec-1: 35
  cec-1: 35
  cec-1: 35
  cec-1: 35
  cec-1: 30:04
'''Print sections only'''
  '''sigrok-cli -i data.sr -P cec:CEC=CEC -A cec=sections'''
  cec-1: HDR: Tuner_1, TV | OPC: IMAGE_VIEW_ON | R: ACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1  HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, Broadcast | OPC: ACTIVE_SOURCE | OPS: 0x10, 0x00 | R: ACK
  cec-1: HDR: Tuner_1, TV | OPC: GIVE_DEVICE_POWER_STATUS | R: ACK
  cec-1: HDR: TV, Tuner_1 | OPC: REPORT_POWER_STATUS | OPS: 0x01 | R: ACK
  cec-1: HDR: Tuner_1, TV | OPC: USER_CONTROL_PRESSED | OPS: 0x6d | R: ACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, TV | OPC: IMAGE_VIEW_ON | R: ACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, TV | OPC: TEXT_VIEW_ON | R: ACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, TV | OPC: IMAGE_VIEW_ON | R: ACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, TV | OPC: GIVE_DEVICE_POWER_STATUS | R: ACK
  cec-1: HDR: TV, Tuner_1 | OPC: REPORT_POWER_STATUS | OPS: 0x01 | R: ACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, TV | OPC: IMAGE_VIEW_ON | R: ACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
  cec-1: HDR: Tuner_1, TV | OPC: GIVE_DEVICE_POWER_STATUS | R: ACK
  cec-1: HDR: TV, Tuner_1 | OPC: REPORT_POWER_STATUS | OPS: 0x01 | R: ACK
[[Category:Protocol decoder]]

Revision as of 18:24, 3 November 2019

cec
File:Cec hdmi pinout.png
Name cec
Description HDMI Consumer Electronics Control (CEC) protocol.
Status supported
License GPLv2+
Source code decoders/cec
Input logic
Output cec
Probes cec


Consumer Electronics Control (CEC) is a feature of HDMI designed to allow users to command and control devices connected through HDMI

Hardware

CEC Bus can be found in PIN 13 of the HDMI connector:

File:Cec hdmi pinout.png

Protocol

It is a one-wire bidirectional serial bus that is based on the CENELEC standard AV.link protocol to perform remote control functions.

CEC is a separate electrical signal from the other HDMI signals. This allows a device to disable its high-speed HDMI circuitry in sleep mode, but be woken up by CEC. It is a single shared bus, which is directly connected between all HDMI ports on a device, so it can flow through a device which is completely powered off (not just asleep).

The bus is electrically identical to the AV.link protocol, but CEC adds a detailed higher-level message protocol.

The bus is an open-collector line, somewhat like I²C, passively pulled up to +3.3 V, and driven low to transmit a bit.

Pulseview screenshots

  • Ping (poll) frames

  • Vendor command frame

Usage examples

Print all annotations (very verbose) 

 sigrok-cli -i data.sr -P cec:CEC=CEC
 
 cec-1: ST
 cec-1: 0
 cec-1: 0
 cec-1: 1
 cec-1: 1
 cec-1: 0
 cec-1: 0
 cec-1: 0
 cec-1: 0
 cec-1: 0x30
 cec-1: EOM=N
 cec-1: ACK
 cec-1: 0
 cec-1: 0
 cec-1: 0
 cec-1: 0
 cec-1: 0
 cec-1: 1
 cec-1: 0
 cec-1: 0
 cec-1: 0x04
 cec-1: EOM=Y
 cec-1: ACK
 cec-1: 30:04
 cec-1: HDR: Tuner_1, TV | OPC: IMAGE_VIEW_ON | R: ACK


Print frames only 

 sigrok-cli -i data.sr -P cec:CEC=CEC -A cec=frames

 cec-1: 30:04
 cec-1: 35
 cec-1: 35
 cec-1: 3f:82:10:00
 cec-1: 30:8f
 cec-1: 03:90:01
 cec-1: 30:44:6d
 cec-1: 35
 cec-1: 35
 cec-1: 30:04
 cec-1: 35
 cec-1: 35
 cec-1: 30:0d
 cec-1: 35
 cec-1: 35
 cec-1: 35
 cec-1: 35
 cec-1: 30:04
 cec-1: 35
 cec-1: 35
 cec-1: 30:8f
 cec-1: 03:90:01
 cec-1: 35
 cec-1: 35
 cec-1: 35
 cec-1: 35
 cec-1: 35
 cec-1: 35
 cec-1: 30:04

Print sections only 

 sigrok-cli -i data.sr -P cec:CEC=CEC -A cec=sections

 cec-1: HDR: Tuner_1, TV | OPC: IMAGE_VIEW_ON | R: ACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1   HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, Broadcast | OPC: ACTIVE_SOURCE | OPS: 0x10, 0x00 | R: ACK
 cec-1: HDR: Tuner_1, TV | OPC: GIVE_DEVICE_POWER_STATUS | R: ACK
 cec-1: HDR: TV, Tuner_1 | OPC: REPORT_POWER_STATUS | OPS: 0x01 | R: ACK
 cec-1: HDR: Tuner_1, TV | OPC: USER_CONTROL_PRESSED | OPS: 0x6d | R: ACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, TV | OPC: IMAGE_VIEW_ON | R: ACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, TV | OPC: TEXT_VIEW_ON | R: ACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, TV | OPC: IMAGE_VIEW_ON | R: ACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, TV | OPC: GIVE_DEVICE_POWER_STATUS | R: ACK
 cec-1: HDR: TV, Tuner_1 | OPC: REPORT_POWER_STATUS | OPS: 0x01 | R: ACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, TV | OPC: IMAGE_VIEW_ON | R: ACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
 cec-1: HDR: Tuner_1, TV | OPC: GIVE_DEVICE_POWER_STATUS | R: ACK
 cec-1: HDR: TV, Tuner_1 | OPC: REPORT_POWER_STATUS | OPS: 0x01 | R: ACK
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