ASM1812 EEPROM

[NiHaoMike]

I have an ASM1812 card that breaks out a PCIe x4 port to 6 x1 ports. While quite useful, I think it would be even more useful if I could reprogram it to (for example) 2 x2 ports and 2 x1 ports. There's an unpopulated spot for an I2C EEPROM which I presume is used to program the configuration, and its absence just has it operate with its default configuration.

The problem is that I couldn't find any hint of information on what should be written to the EEPROM to make it work differently. Anyone might know something in that regard?

[RayeR]

What PCIe switch is inside? You need to get datasheet to find registers description and EEPROM programming. I have some experiences with Pericom PI7C9X2G1224GP that use SPI flash for config (W25X10CLSNIG) but it can be also reprogrammed later.

[luudee]

The configuration is done by pulling certain pins high or low during reset.
If there is no eeprom, it means it has the firmware is build in or isn't required.
Most of those devices are pin compatible, upper number indicated generation ...

Cheers,
luudee

[NiHaoMike]

What PCIe switch is inside? You need to get datasheet to find registers description and EEPROM programming. I have some experiences with Pericom PI7C9X2G1224GP that use SPI flash for config (W25X10CLSNIG) but it can be also reprogrammed later.

The chipset is ASM1812 from Asmedia.
https://www.asmedia.com.tw/product/1e2yQ48sx5HT2pUF/b7FyQBCxz2URbzg0
Basically no documentation seems to exist online.