TE0820 Custom Carrier DisplayPort Implementation

[mer]

Using TEBF0808 as a reference I noticed that the the DPAUX signals (OE, HPD, AUX_IN, AUX_OUT) are routed to one of the CPLDs. I'm assuming this is because these signals are 3.3V and the CPLD is essentially serving as a level shifter to 1.8V since all MIO are 1.8V on the carrier. Would it be appropriate to use a SN74A type level shifter instead? Should I remove the resistors (R40, R41) from HPD? Any other considerations? Thank you.

[Vitali]

Hi,
TEBF0808 is the carrier board for TE0803/TE0807/TE0808. If you are using the TE0820 micromodule, the MIO Bank501 is connected to 3.3V and you don't need to use a level translator. The HPD signal should be pulled down by at least 100k and you can remove the resistors R40, R41 in your project.

[mer]

Oops, messed up the title. Making a custom carrier for TE0808 so MIO is all 1.8V.

[Vitali]

If you don't like using a CPLD, you can use a level translator as an alternative.

[George]

If the DPAUX signals are originally at 3.3V and the carrier board operates with 1.8V MIO (Multiplexed I/O) voltage, using a level shifter is indeed a suitable approach to ensure proper voltage translation. The SN74A series level shifters, which are specifically designed for voltage level conversion, can be a suitable choice for this purpose.

Regarding the resistors (R40, R41) on the HPD (Hot Plug Detect) signal, their presence or removal depends on the specific design and requirements of the system. These resistors are often used for managing the hot-plug detection functionality. If you are modifying the design, it's advisable to consult the relevant documentation or consult with the manufacturer to understand the purpose of these resistors and whether they should be removed or kept in your specific configuration.