HDMI 2.1 TX Subsystem Interrupt Controlling Layer - 1.2 English

HDMI 2.1 Transmitter Subsystem Product Guide (PG350)

Document ID
PG350
Release Date
2022-04-27
Version
1.2 English

The following table shows the mapping between the HDMI 2.1 TX, HDMI 2.1 TX SS interrupts and HDMI 2.1 TX controlling layer events that trigger state transitions.

Table 1. Interrupt Sources and Application Interrupt Controlling State Machine Layer Mapping
HDMI 2.1 TX Interrupts HDMI 2.1 TX SS Callback HDMI 2.1 TX Interrupt Controlling Layer Event Label
HPD

XV_HDMITXSS1_HANDLER_CONNECT

XV_HDMITXSS1_HANDLER_TOGGLE

XV_TX_HDMI_EVENT_DISCONNECTED

XV_TX_HDMI_EVENT_CONNECTED

A

B

Link Ready

XV_HDMITXSS1_HANDLER_STREAM_UP

XV_HDMITXSS1_HANDLER_STREAM_DOWN

Note: Two callbacks are mapped to the same interrupt source.

Link Ready rising edge: Stream Up

Link Ready falling edge: Stream Down

XV_TX_HDMI_EVENT_STREAMUP

XV_TX_HDMI_EVENT_STREAMDOWN

C

D

Vertical Sync XV_HDMITXSS1_HANDLER_VS XV_TX_HDMI_EVENT_VSYNC E
Video Bridge Unlocked XV_HDMITXSS1_HANDLER_BRDGLOCK XV_HDMITXSS1_HANDLER_BRDGUNLOCK XV_TX_HDMI_EVENT_BRDGUNLOCKED F
Video Bridge Overflow XV_HDMITXSS1_HANDLER_BRDGOVERFLOW XV_TX_HDMI_EVENT_BRDGOVERFLOW G
Video Bridge Underflow XV_HDMITXSS1_HANDLER_BRDGUNDERFLOW XV_TX_HDMI_EVENT_BRDGUNDERFLOW H
FRL Interrupt

XV_HDMITXSS1_HANDLER_FRL_CONFIG

XV_HDMITXSS1_HANDLER_FRL_FFE

XV_HDMITXSS1_HANDLER_FRL_START

XV_HDMITXSS1_HANDLER_FRL_STOP

XV_HDMITXSS1_HANDLER_TMDS_CONFIG

XV_TX_HDMI_EVENT_FRLCONFIG

XV_TX_HDMI_EVENT_FRLFFE

XV_TX_HDMI_EVENT_FRLSTART

XV_TX_HDMI_EVENT_FRLSTOP

XV_TX_HDMI_EVENT_TMDSCONFIG

I

J

K

L

M

HDCP 1.4 Interrupt      
HDCP 1.4 Timer Interrupt      
HDCP 2.3 Interrupt      
HDCP 2.3 Timer Interrupt      
 

XV_HDMITXSS1_HANDLER_HDCP_AUTHENTICATE

XV_HDMITXSS1_HANDLER_HDCP_DOWNSTREAM_TOPOLOGY_AVAILABLE

XV_HDMITXSS1_HANDLER_HDCP_UNAUTHENTICATED

Note: This callback function is not directly mapped to any interrupt source. Instead it is executed when the HDCP authentication state machine has reached the authenticated state.
   
Dynamic HDR MTW Interrupt XV_HDMITXSS1_HANDLER_ DYNHDR_MTW    

The following figure shows the control flow of the HDMI 2.1 TX Subsystem interrupts received by the application. See the previous table for more details on the mapping of interrupts and events. The event LABEL from the previous table is marked as the event cause of state transitions in the following figure.

Figure 1. HDMI 2.1 Subsystem Interrupt Control

In the HDMI 2.1 TX Interrupt controlling layer each interrupt received from the HDMI 2.1 TX subsystem has its corresponding state. This allows the application to track the last received interrupt and control the behavior of HDMI 2.1 TX based on the next interrupt received. This allows the application to control the flow of HDMI 2.1 TX subsystem interrupts from the connection of the TX cable to the disconnection of the TX cable.

The control of flow and transition from one interrupt state to another can be modified to accommodate a required level of leniency or strictness. The previous figure shows a minimalist and strict transition between the states.

The state transitions in the HDMI 2.1 TX interrupt controlling layer can be changed and updated depending on the extent of strictness of leniency that you want in serving the interrupts from the HDMI 2.1 TX subsystem. The application implements a formal and minimal flow control of the interrupts.

The following is a description of the HDMI 2.1 TX states and transitions that are allowed on the state. You are at liberty to allow or disallow transitions as needed.

  • STATE CONNECTED - The state machine transitions to this state after receiving the connect interrupt from the HDMI 2.1 TX subsystem. Ideally, the transition to this state should happen only from the disconnected state.
  • STATE FRL CONFIG - The state machine transitions to this state after receiving the frl config request interrupt from the HDMI 2.1 TX subsystem. The state machine transitions to this state from all states except disconnect. In case of multiple frl config requests, each interrupt is serviced exclusively.
  • STATE TMDS CONFIG - The state machine transitions to this state after receiving the tmds config request interrupt from the HDMI 2.1 TX subsystem. The state machine transitions to this state from all states except disconnect. In case of multiple tmds config requests, each interrupt is serviced exclusively, although multiple tmds request interrupts should not be expected.
  • STATE FRL FFE - The state machine transitions to this state after receiving the frl ffe interrupt from the HDMI 2.1 TX subsystem. The state machine transitions to this state from either the frl config, frl start or frl stop states. FRL ffe received on any other state is ignored.
  • STATE FRL START - The state machine transitions to this state after receiving the frl start interrupt from the HDMI 2.1 TX subsystem. The state machine transitions to this state from either the frl config, frl ffe or frl stop states. FRL start received on any other state is ignored.
  • STATE FRL STOP - The state machine transitions to this state after receiving the frl stop interrupt from the HDMI 2.1 TX subsystem. The state machine transitions to this state from frl config, frl ffe, frl start, stream on and vsync states.
  • STATE STREAM ON - The state machine transitions to this state after receiving the stream up interrupt from the HDMI 2.1 TX subsystem. The state machine transitions to this state only from the frl start, tmds config and stream off states.
  • STATE VSYNC - The state machine transitions to this state after receiving the vsync interrupt from the HDMI 2.1 TX subsystem. The state machine transitions to this state only from the stream on and bridge unlocked state states. As multiple vsync interrupts are received., each interrupt is serviced exclusively. A vsync interrupt received when the state machine is in any state other than stream on, bridge unlocked or vsync is ignored.
  • STATE BRIDGE UNLOCKED - The state machine transitions to this state after receiving the bridge unlocked interrupt from the HDMI 2.1 TX subsystem. Ideally, the transition to this state happens only from the vsync or stream on state.
  • STATE STREAM OFF - The state machine will transition to this state upon receiving the stream down interrupt from the HDMI 2.1 TX subsystem drivers. Transition to this state can happen from any state.
  • STATE DISCONNECTED - This is the default state to which the state machine is initialized. The state machine will transition to this state upon receiving the disconnect interrupt from the HDMI 2.1 TX subsystem drivers. Transition to this state must happen from every state.