AUX Read Transaction - 3.0 English

DisplayPort 1.4 TX Subsystem Product Guide (PG299)

Document ID
PG299
Release Date
2022-05-04
Version
3.0 English

The AUX read transaction is prepared by writing the transaction address to the AUX_ADDRESS register. Once set, the command and the number of bytes to read are written to the AUX_COMMAND register. After initiating the transfer, the host should wait for an interrupt or poll the INTERRUPT_STATUS register to determine when a reply is received.

When the REPLY_RECEIVED signal is detected, the host might then read the requested data bytes from the AUX_REPLY_DATA register. This register provides a single address interface to a byte FIFO which is 16 elements deep. Reading from this register automatically advances the internal read pointers for the next access.

The following figure shows the flow of an AUX read transaction.
Figure 1. AUX Read Transaction