SPRUJ66B February 2023 – September 2025
The DSS (Display Sub system) interface from AM62A SOC is used on the SKEVM to provide a HDMI Interface through a standard Type-A Connector. The SKEVM features a SiI9022A HDMI Transmitter from Lattice semiconductors to convert the 24bit Parallel RGB DSS output stream as well as McASP1 signals to a HDMI-compliant digital audio and video signal.
The Data mapping format used is RGB888. The data bus width is 24-bits.
To use the SiI9022A, the SOC needs to setup the device. This is done via theI2C1 interface between the SOC and the SiI9022A. SoC_I2C1 instance connected to the HDMI Transmitter accesses the compatible mode registers, the TPI registers, and the CPI registers. Audio Data is sent from the SOC to HDMI transmitter through the McASP1 instance. HDMI_I2C Bus accesses the EDID and HDCP data on an attached sink device.
TMDS Differential data pairs along with the differential clock signals from the transmitter are connected to the HDMI connector through the HDMI ESD device Mfr Part# TPD12S016PWR. This device also acts as a load switch to limit current supplied to the HDMI connector from board 5V supply.
The HDMI Framer is powered using 3.3V Board IO Supply and 1.2V for the AVCC and DVCC supply by a dedicated LDO.
Figure 2-15 HDMI Interface Block
Diagram