DS160PR822: Use in I2C slave mode for PCIe applications?

Terje Melsom

Part Number: DS160PR822
Other Parts Discussed in Thread: DS160PR810

We are considering to use a handful of the DS160PR822 devices in a PCIe application.

The datasheet says: "The device is in normal operation with PCIe state machine enabled by RX_DET = L1/L2/L3". However this is a shared pin: RX_DET / SCL. For operation in I2C mode, SCL must have a pull-up. L1 and L2 requires pull-down and L3 requires an 'open'. Is it possible to enable the PCIe state machine with the RX_DET / SCL pin connected to an I2C bus?

Terje

over 5 years ago

0 Nasser Mohammadi over 5 years ago

TI__Guru* 93570 points

Hi Terje,

Yes it is possible. There is a register - reg 0x03 - that allows RX detect override pin function. Using this register, you can set to auto rx detect as required by PCIe spec. Please refer to the DS160PR810 programming guide for details about this register.

Regards,, Nasser

0 Terje Melsom over 5 years ago in reply to Nasser Mohammadi

Prodigy 55 points

Wouldn't this lead to a requirement that the device must be initialized before PCIe reset is de-asserted? Our intention was to use the 100ms period from end of PCIe reset to devices have to be ready to respond to initialize the device.

Terje

0 Nasser Mohammadi over 5 years ago in reply to Terje Melsom

TI__Guru* 93570 points

Hi Terje,

Agreed. In this case, we need to use EEPROM. Upon power up, device automatically loads from EEPROM. This means device is initialized as soon as power is present.

Regards,, Nasser

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DS160PR822: Use in I2C slave mode for PCIe applications?