[i.MX6] One question about PCIe I/F

[Paul_Kang]

I have one quesiton about PCIe circuit connection to i.MX6 device for proper PCI device operation. Could anybody answer to it?

The question is, actually, it is very clear about Sabre A (It only has PCIe data connection to mini PCI connector) I but in case of Sabre SD, I found there are some other signals connected to mini PCI connector.

Below is my understanding. If there is anything incorrect, please correct it.

1. PCIe_CRXM/P, PCIe_CTXM/P à PCIe interface
2. PCIe_CREFCLKM/P à CLK from CLK0_N/P or CLK1_N/P of i.MX6
3. PCIe_UIM_xxx à All for SIM card and not connected to i.MX6
4. PCIe_USBDM/P à USB HOST port of i.MX6
5. LED_xxxx_B à LED on board. Not connected to i.MX6
6. PCIe_DIS_B, PCIe_RST_B, PCIe_WAKE_B à GPIO, can be connected to any GPIO of i.MX6
7. PCIe_SMC_CLK/DAT à I2C I/F and connected to i.MX6 I2C I/F

Thank you!

Paul

[Paul_Kang]

Hi, Weidong,

It is clceared now. thank you for your answer.

[weidong_sun]

Hello,jounnii,

      On mini-PCIE(J1)connector of sabreSD board, there are 2 kinds of signals : One is PCIe signal; the other is 3G signal. Normally, definitions on mini-PCIE connector are for 3G module. But in order to connect PCIe signals in i.mx6 outside, designers used those reserved pins on J1 for PCIe signals.

       PCIe signals are : CLK1P/CLK1N, PCIE_RXM/PCIE_RXP, PCIE_TXM/PCIE_TXP. PCIE_WAKE_B is a GPIO on i.mx6, you can changed it to another GPIO, and configure it as input.

       Other signals on J1 are for 3G module.

Regards,

Weidong

[Paul_Kang]

Hi Weidong,

Thank you for your answer.

Regarding 3G signal,

can I say, PCIe_DIS_B, PCIe_RST_B is GPIO and PCIe_SMC_CLK/DAT is I2C?

I am not sure if such additional signals are within PCIe standard or not.

Best regards,

Paul

[weidong_sun · Accepted solution]

Hello, jounnii,

     >>can I say, PCIe_DIS_B, PCIe_RST_B is GPIO and PCIe_SMC_CLK/DAT is I2C?

         Yes , right.

     >>I am not sure if such additional signals are within PCIe standard or not.

        additional signals are for 3G module. Not PCIe signals. you can confirm them by PCIe standard specification.

        Don't confuse connector named mini-PCIe, mimi-PCIe is only a name for 3G module. But PCIe is a standard signal specificaion. For PCIe with 1 lane interface, it has 3 diffrential pairs : CLK+/CLK-, RX+/RX- and TX+/TX- .

       Do I describe it clearly ?

Regards,

Weidong