Card Edge Connector (miniPCIe)
The Nagami features a standard miniPCIe card edge connector with a custom pinout tailored for extended embedded system functionality. This connector supports a variety of alternate functions, allowing flexible hardware expansion and customization.
Pinout Description
The table below lists the pinout of the Card Edge connector, divided into TOP and BOTTOM rows. For each pin, the CPU pin or GPIO name is provided along with its default assigned function.
| TOP Pin | Signal Name / CPU Pin | Default Function | BOTTOM Pin | Signal Name / CPU Pin | Default Function |
|---|---|---|---|---|---|
| 1 | GND | Power | 2 | +3.3V | Power |
| 3 | MDI_TX- | Ethernet MDI | 4 | GND | Power |
| 5 | MDI_TX+ | Ethernet MDI | 6 | PF5 | SDC0-D2 |
| 7 | MDI_RX- | Ethernet MDI | 8 | PF4 | SDC0-D3 |
| 9 | MDI_RX+ | Ethernet MDI | 10 | PF3 | SDC0-CMD |
| 11 | GND | Power | 12 | PF2 | SDC0-CLK |
| 13 | ETH_LED1 | Ethernet LEDs | 14 | PF1 | SDC0-D0 |
| 15 | ETH_LED2 | Ethernet LEDs | 16 | PF0 | SDC0-D1 |
Mechanical Key
| TOP Pin | Signal Name / CPU Pin | Default Function | BOTTOM Pin | Signal Name / CPU Pin | Default Function |
|---|---|---|---|---|---|
| 17 | PB6 | UART3-TX | 18 | GND | Power |
| 19 | PB7 | UART3-RX | 20 | PF6 | GPIO |
| 21 | GND | Power | 22 | nRESET | Reset Input |
| 23 | USB1_D- | USB-Host D- | 24 | +3.3V | Power |
| 25 | USB1_D+ | USB-Host D+ | 26 | GND | Power |
| 27 | GND | Power | 28 | PD22 | GPIO |
| 29 | PD16 | GPIO | 30 | PD20 | TWI2-SCK |
| 31 | PD15 | SPI1-WP | 32 | PD21 | TWI2-SDA |
| 33 | PD14 | SPI1-HOLD | 34 | GND | Power |
| 35 | PD10 | SPI1-CS | 36 | USB0_D- | USB-OTG D- |
| 37 | PD11 | SPI1-CLK | 38 | USB0_D+ | USB-OTG D+ |
| 39 | PD13 | SPI1-MISO | 40 | GND | Power |
| 41 | PD12 | SPI1-MOSI | 42 | PG13 | I2S1-BCLK |
| 43 | GND | Power | 44 | PG12 | I2S1-LRCK |
| 45 | PB5 | CAN1-RX | 46 | PG14 | I2S1-DIN0 |
| 47 | PB4 | CAN1-TX | 48 | PG15 | I2S1-DOUT0 |
| 49 | PB3 | CAN0-RX | 50 | GND | Power |
| 51 | PB2 | CAN0-TX | 52 | +3.3V | Power |
Note: The pin numbering corresponds to the standard miniPCIe connector pin sequence.
Alternate Functions
Below is an illustration showing the possible alternate functions for the Card Edge connector pins:
Default Interfaces
Below are descriptions of the pins for the default interfaces available on the Card Edge connector.
Power and Reset
The Module requires a single +3.3V power supply and includes several ground pins for power distribution. It also has a reset pin to allow external reset control.
- GND: Ground pins for power supply.
- Pins: 1, 4, 11, 18, 21, 26, 27, 34, 40, 43, 50
- +3.3V: Power supply pins providing 3.3V to the module.
- Pins: 2, 24, 52
- nRESET: Reset input pin to reset the module.
- Pin: 22
- Note: The module has an internal pull-up resistor, so it should be pulled low externally to trigger a reset.
Ethernet
The Card Edge connector provides a single Ethernet interface using MDI (Media Dependent Interface) signals. This allows the carrier board to connect to a simple MagJack connector or Magnetics for Ethernet communication.
- MDI_TX-: Ethernet transmit negative signal.
- Pin: 3
- MDI_TX+: Ethernet transmit positive signal.
- Pin: 5
- MDI_RX-: Ethernet receive negative signal.
- Pin: 7
- MDI_RX+: Ethernet receive positive signal.
-
Pin: 9
-
ETH_LED1: Ethernet link/activity LED 1.
- Pin: 13
- ETH_LED2: Ethernet link/activity LED 2.
- Pin: 15
USB
The Card Edge connector provides two USB interfaces, one for USB OTG and one for USB Host.
- USB0_D-: USB OTG data negative signal.
- Pin: 36
- USB0_D+: USB OTG data positive signal.
- Pin: 38
- USB1_D-: USB Host data negative signal.
- Pin: 23
- USB1_D+: USB Host data positive signal.
- Pin: 25
CAN Bus
The Card Edge connector supports two CAN interfaces for robust communication in industrial and automotive applications. The CAN pins are designed to connect to standard CAN transceivers.
- CAN0_RX: CAN0 receive signal.
- Pin: 49
- CAN0_TX: CAN0 transmit signal.
- Pin: 51
- CAN1_RX: CAN1 receive signal.
- Pin: 45
- CAN1_TX: CAN1 transmit signal.
- Pin: 47
I2C
The Card Edge connector includes an I2C interface for connecting to various peripherals. The TWI2 interface is used for this purpose.
- TWI2_SCK: I2C clock signal.
- Pin: 30
- TWI2_SDA: I2C data signal.
- Pin: 32
I2S
The Card Edge connector provides an I2S interface for audio applications, allowing connection to audio codecs or digital microphones.
- I2S1_BCLK: I2S bit clock signal.
- Pin: 42
- I2S1_LRCK: I2S left/right clock signal.
- Pin: 44
- I2S1_DIN0: I2S data input channel 0.
- Pin: 46
- I2S1_DOUT0: I2S data output channel 0.
- Pin: 48
UART
The Card Edge connector includes a UART interface for serial communication, which can be used for debugging or communication with other devices. By default this UART is used for the bootloader and linux console.
- UART3_TX: UART transmit signal.
- Pin: 17
- UART3_RX: UART receive signal.
- Pin: 19
SD
The Card Edge connector provides an SD interface for connecting to SD cards or SDIO devices. This interface supports 4-bit wide data transfer.
- SDC0_CLK: SD clock signal.
- Pin: 12
- SDC0_CMD: SD command signal.
- Pin: 10
- SDC0_D0: SD data line 0.
- Pin: 14
- SDC0_D1: SD data line 1.
- Pin: 16
- SDC0_D2: SD data line 2.
- Pin: 6
- SDC0_D3: SD data line 3.
- Pin: 8
SPI
The Card Edge connector includes an SPI interface for high-speed communication with peripherals such as sensors or flash memory. The SPI1 interface is used for this purpose.
- SPI1_CLK: SPI clock signal.
- Pin: 37
- SPI1_MOSI: SPI master out, slave in signal.
- Pin: 41
- SPI1_MISO: SPI master in, slave out signal.
- Pin: 39
- SPI1_CS: SPI chip select signal.
- Pin: 35
- SPI1_WP: SPI write protect signal (optional).
- Pin: 31
- SPI1_HOLD: SPI hold signal (optional).
- Pin: 33
GPIO
The remaining three pins on the Card Edge connector can be used as general-purpose input/output (GPIO) pins, allowing for additional custom functionality. They are intended to be used for features such as the USB_OTG ID pin, SDC0 card detect, or interrupts for connected peripherals.
- GPIO: General-purpose input/output pins.
- Pin: 20 (PF6)
- Pin: 28 (PD22)
- Pin: 29 (PD16)