SLLA633 May   2024 TMDS1204

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Waking Up an HDMI Sink Device
    1. 1.1 Reasons for Wake Up Failure
  5. 2Communicating Without CEC
  6. 3HDMI1.4/2.0/2.1 Detection Methodology
  7. 4Summary
  8. 5References

3 HDMI1.4/2.0/2.1 Detection Methodology

TI’s TMDS1204 is a HDMI2.1 Hybrid Redriver capable of supporting data rates up to 12Gbps. TMDS1204 is backwards compatible for HDMI 1.4b and HDMI 2.0b. The TMDS1204 is a hybrid redriver supporting both source and sink applications. A hybrid redriver can operate either in a linear or limited redriver function.

The TMDS1204 has a SIGDET_OUT open drain output. When TMDS1204 Standby mode is enabled and Swap function is disabled, the TMDS1204 looks for a signal on either IN_CLK (if HDMI 1.4 or 2.0) or IN_D2 (if HDMI 2.1). When the Standby mode is enabled and the Swap function is enabled, the TMDS1204 looks for a signal on either IN_CLK (if HDMI 2.1) or IN_D2 (if HDMI 1.4 or 2.0).

When standby state is enabled, the TMDS1204 can assert the SIGDET_OUT pin low whenever the TMDS1204 exits the standby state and can de-assert SIGDET_OUT pin when entering power down or standby state.

The SIGDET_OUT pin can then be used to drive an MCU. Once the wake-up signal is detected, then the MCU wakes up the video processor and the video processor can enable RTerm in HDMI Rx for normal operation.

TMDS1204 Implementation Example Block Diagram Figure 3-1 TMDS1204 Implementation Example Block Diagram

Please note, this detection scheme does not limit to HDMI2.1, the detection scheme also be used for HDMI1.4 and 2.0.