SPRUJ63A September 2022 – October 2023
The Serdes0 interface of AM64x/AM243x is used to implement a x1 lane PCIe interface with the signals routed to a x4 PCIe slot connector. PCIE-064-02-F-D-TH connector from Samtec is be used for the PCIe interface and this connector meets the PCIe CEM v2.0 specification both physically and electrically. PCIE-064-02-F-D-TH connector is designed to support a 25 W slot including 2.1A for the 12 V rail and 3 A for the 3.3 V rail. The PCIe interface is designed to support either root complex operation or endpoint operation with a cross over cable. SoC_I2C1 is used for control purpose. The link activation signal from PCIe connectors is pulled up to VCC3V3_SYS.
Clock: SERDES REFCLK is routed to the PCIe REF CLK pins to allow either receiving or providing a clock from the connector (no separate PLL to generate PCIe REF CLK available on the EVM).
Hot plug: The PRSNT1# and PRSNT2# signals are the hot plug presence detect signals. The PRSNT2# is pulled up and PRSNT1# is connected to ground so that PRSNT2# is pulled low when a daughter card is plugged in. A 3 pin header (J35) is provided to choose between RC and EP mode.
Reset: A 3 pin header (J34) is provided to select the reset source for host and endpoint PCIe operation. In case of host mode, PCIe_RST_OUT signal from IO Expander and RESETSTATz signal from SoC are ANDed and the output is connected to PCIe connector through 3 pin header. A jumper is mounted for the connectivity. Whereas in case of PCIe end point operation, the AM64x SoC receives reset signal from the add-on card and passed on to the MCU_PORz pin. The reset signal is connected to 3 pin header and the selection needs to be made with a jumper.
The PCIe x4 Connector JTAG signals are unused and test points are provided on the signals.
Table 3-22 describes the jumper options used to select if the EVM operates in Root Complex mode or in End Point mode.
Root Complex | End Point | |
---|---|---|
1x3 header J34 and J35 | Short 1 and 2 | Short 2 and 3 |
Pin No. | Side A of PCIe Connector | GP Board Signal | Side B of PCIe Connector | GP Board Signal |
---|---|---|---|---|
1 | PRSNT1# | J35.3 | +12V | VDD_12V |
2 | +12V | VDD_12V | +12V | VDD_12V |
3 | +12V | VDD_12V | +12V | VDD_12V |
4 | GND | GROUND | GND | GROUND |
5 | JTAG2 | TP | SMCLK | SoC_I2C1_CLK |
6 | JTAG3 | TP | SMDATA | SoC_I2C1_SDA |
7 | JTAG4 | TP | GND | GROUND |
8 | JTAG5 | TP | +3V3 | VCC3V3_SYS |
9 | +3V3 | VCC3V3_SYS | JTAG1 | TP |
10 | +3V3 | VCC3V3_SYS | 3V3 VAUX | VCC3V3_SYS |
11 | PERST# | J24.2 | WAKE# | Pulled up to VCC3V3_SYS |
12 | GND | GROUND | RSVD4 | Pulled up to VCC3V3_SYS |
13 | REFCLK+ | SERDES_REFCLK0P | GND | GROUND |
14 | REFCLK- | SERDER_REFCLK0N | PETp0 | SERDES_TXP0 |
15 | GND | GROUND | PETn0 | SERDES_TXN0 |
16 | PERp0 | SERDES_RXP0 | GND | GND |
17 | PERn0 | SERDES_RXN0 | PRSNT2#_1 | J35.2 |
18 | GND | GROUND | GND | GROUND |
19 | RSVD1 | NC | PETp1 | NC |
20 | GND | GROUND | PETn1 | NC |
21 | PERp1 | NC | GND | GROUND |
22 | PERn1 | NC | GND | GROUND |
23 | GND | GROUND | PETp2 | NC |
24 | GND | GROUND | PETn2 | NC |
25 | PERp2 | NC | GND | GROUND |
26 | PERn2 | NC | GND | GROUND |
27 | GND | GROUND | PETp3 | NC |
28 | GND | GROUND | PETn3 | NC |
29 | PERp3 | NC | GND | GROUND |
30 | PERn3 | NC | RSVD3 | NC |
31 | GND | GROUND | PRSNT2#_2 | NC |
32 | RSVD2 | NC | GND | GROUND |