Low Speed I/O Expansion Connectors - SiFive HiFive Unleashed Getting Started Manual

VDD_1V8: 1.8V I/O voltage from HiFive Unleashed to the FMC carrier card.
PG_M2C: Open-drain, active high power good signal to indicate that HiFiveUnleashed has pow-
ered up correctly. The pull up resistor is on the FMC carrier card.
PRSNT_M2C_L: Active-low signal to indicate to the FMC carrier card that HiFive Unleashed is
present. The pull up resistor is on the FMC carrier card.
All other pins are No Connect on the FMC connector.

8.2 Low Speed I/O Expansion Connectors

There are two low speed I/O expansion connectors, a 2mm pitch 2x20 and a 2mm pitch 2x10
female headers.
The 2x20 connector follows the 96Boards EE specification expansion connector pinout. All I/O
voltage are at 1.8V.
Net Name
GND
No Connect
UART0_TX
UART0_RX
No Connect
UART1_TX
UART1_RX
I2C0_SCL
I2C0_SDA
No Connect
No Connect
GPIO0
GPIO2
GPIO4
GPIO6
GPIO8
GPIO15
VDD_1V8
VDD_5V0
GND
Table 3: 2x20 Low Speed I/O Expansion Connector Pinout
The 2x10 connector has additional low speed I/Os. All I/O voltage are at 1.8V.
Pin Name #
GND 1
UART0_CTS 3
UART0_TXD 5
UART0_RXD 7
UART0_RTS 9
UART1_TXD 11
UART1_RXD 13
I2C0_SCL 15
I2C0_SDA 17
I2C1_SCL 19
I2C1_SDA 21
GPIO-A 23
GPIO-C 25
GPIO-E 27
GPIO-G 29
GPIO-I 31
GPIO-K 33
+1V8 35
+5V 37
GND 39
# Pin Name
2 GND
4 PWR_BTN_N
6 RST_BTN_N
8 SPI0_SCLK
10 SPI0_DIN
12 SPI0_CS
14 SPI0_DOUT
16 PCM_FS
18 PCM_CLK
20 PCM_DO
22 PCM_DI
24 GPIO-B
26 GPIO-D
28 GPIO-F
30 GPIO-H
32 GPIO-J
34 GPIO-L
36 SYS_DCIN
38 SYS_DCIN
40 GND
23
Net Name
GND
PWR_BTN_N
RESET_N
QSPI1_SCK
QSPI1_DQ1
QSPI1_CS0
QSPI1_DQ0
No Connect
No Connect
No Connect
No Connect
GPIO1
GPIO3
GPIO5
GPIO7
GPIO9
No Connect
VDD_DCIN
VDD_DCIN
GND