Olimex Support Forum

OLinuXino Android / Linux boards and System On Modules => A20 => Topic started by: Oleg Strelkov on December 07, 2020, 12:16:04 PM

Title: PCIe interface on A20-SOM204-EVB board
Post by: Oleg Strelkov on December 07, 2020, 12:16:04 PM
Hi, Olimex!

I bought a A20-SOM204-EVB board.
It has a PCIe connector.
Does this interface work with the A20 processor?

Oleg.
Title: Re: PCIe interface on A20-SOM204-EVB board
Post by: LubOlimex on December 14, 2020, 10:44:49 AM
There is no PCIe on the connector when used with A20-SOM204. A20 has no PCIe support. However, there are some signals that can be connected to the connector, if several resistors are placed (these are not placed by default to avoid multiplexing issues). The LCD signals can be lead to it, refer to the schematic:

https://github.com/OLIMEX/SOM204/blob/master/A20-SOM204/A20-SOM204_Rev_C2.pdf

The connector was added for future SOM designs that might have PCIe.
Title: Re: PCIe interface on A20-SOM204-EVB board
Post by: SukiEgan on December 14, 2020, 07:24:48 PM
Hi...A20-SOM204 accompanies 1GB RAM, discretionary SPI Flash or eMMC Flash up to 64GB, two local Ethernets (this is the lone A20 board with double local Ethernets) Gigabit and Megabit, SATA, etc. The USB3.0 interface and PICe interfaces are not wired. On top on SOM204 stage LCD and extra GPIOs are uncovered on FPC connectors.

printed circuit board turnkey (https://www.7pcb.com/)
Title: Re: PCIe interface on A20-SOM204-EVB board
Post by: LubOlimex on December 15, 2020, 09:44:26 AM
What SukiEgan is true, notice that while there are double Ethernets, we haven't been able to get them working simultaneously. Only one of them can be used at a time.
Title: Re: PCIe interface on A20-SOM204-EVB board
Post by: Oleg Strelkov on December 16, 2020, 06:14:52 PM
Hi, LubOlimex and SukiEgan,

Thank you for clarification.
I was surprised that this interface is not described in the A20 CPU datasheet, but is present on A20-SOM204-EVB board.
Now I understood that these PCIe and USB 3.0 are reserved for other SOM.

Best regards,
Oleg.