In TMDS mode, a change in the TX reference clock signifies a video format
change, which triggers a series of interrupts until the GT TX attains the TX Reset Done
status. The TX frequency change is based on the toggling (deassertion then assertion) of
the tx_refclk_rdy
port or it can be forced by setting
the TX Frequency Reset bit (bit 3) of the Clock Detector Control register (0x200). This
bit is self-clearing. See HDMI Reference Clock Requirements (link below) for details
about tx_refclk_rdy
port implementation.
There are several API callback hooks that the HDMI GT Controller core executes throughout the HDMI TX operation. If necessary, these callbacks are available for inserting or adding more function calls on top of what is in the software application.
TX FRL mode is entered when the XHdmiphy1_Hdmi21Config
API is called in the application. It requires the
target FRL rate (3, 6, 8, 10, and 12 Gbps) and the number of channels (3 or 4). After
this, it performs all tasks under the TX Timer Timeout Intr to attain TX Alignment Done
status eventually.