Currently I am designing a T2081 based custom board that will communicate with other board FPGA board (MPF300T-FCG484I from Micro-semi) via PCIe. I have following questions to ask?
1)What voltage level do I have to maintain for the PCIe connection to work? As per t2081 datasheet both TX-RX pair along with the SDREFCLK works on 1V but in case of the FPGA, though Tx-Rx works on 1v, PCIe REFCLK voltage level is 2.5V. kindly provide your valuable guidance for the same.
2)Apart from Tx-Rx and REFCLK do I need any other signals to initiate the PCIe Communications between the two boards? If yes, please name them.
3)Please check the connection attached in the PDF format and let me know if this is going to work to start PCIe Communication between the two boards. (i.e. T2081 and FPGA Board)
Attaching the image for your Reference.\
1.Question is not clear. The T2081 complies with PCIe specifications for TX-RX signals. The same compliance is expected on FPGA side, so TX-RX path must be functional. Electrical specifications of SerDes REFCLK can be found in the T2081 data sheet.
2. No other signals are needed.
3. Connections look correct. As I mentioned above, you have to check that electrical levels of the SerDes clock source meet requirements listed in the T2081 data sheet.
It is required to have one AC coupling capacitor per a signal. PCIe specifications recommend to place it near a transmitter. However if PCIe link is routed on the board (no plug-in cards), location of the capacitors is not important.