Data Sheet

Compute Module 3+ Datasheet

Default

GPIO Pull ALT0 ALT1 ALT2 ALT3 ALT4 ALT5

28 None SDA0 SA5 PCM CLK FL0 - -

29 None SCL0 SA4 PCM FS FL1 - -

30 Low TE0 SA3 PCM DIN CTS0 - CTS1

31 Low FL0 SA2 PCM DOUT RTS0 - RTS1

32 Low GPCLK0 SA1 RING OCLK TXD0 - TXD1

33 Low FL1 SA0 TE1 RXD0 - RXD1

34 High GPCLK0 SOE N TE2 SD1 CLK - -

35 High SPI0 CE1 N SWE N - SD1 CMD - -

36 High SPI0 CE0 N SD0 TXD0 SD1 DAT0 - -

37 Low SPI0 MISO SD1 RXD0 SD1 DAT1 - -

38 Low SPI0 MOSI SD2 RTS0 SD1 DAT2 - -

39 Low SPI0 SCLK SD3 CTS0 SD1 DAT3 - -

40 Low PWM0 SD4 - SD1 DAT4 SPI2 MISO TXD1

41 Low PWM1 SD5 TE0 SD1 DAT5 SPI2 MOSI RXD1

42 Low GPCLK1 SD6 TE1 SD1 DAT6 SPI2 SCLK RTS1

43 Low GPCLK2 SD7 TE2 SD1 DAT7 SPI2 CE0 N CTS1

44 None GPCLK1 SDA0 SDA1 TE0 SPI2 CE1 N -

45 None PWM1 SCL0 SCL1 TE1 SPI2 CE2 N -

Table 10: GPIO Bank1 Alternate Functions

Table 9 and Table 10 detail the default pin pull state and available alternate GPIO functions. Most of

these alternate peripheral functions are described in detail in the Broadcom Peripherals Speciﬁcation

document and have Linux drivers available.

9.1.2 Secondary Memory Interface (SMI)

The SMI peripheral is an asynchronous NAND type bus supporting Intel mode80 type transfers at 8 or

16 bit widths and available in the ALT1 positions on GPIO banks 0 and 1 (see Table 9 and Table 10). It

is not publicly documented in the Broadcom Peripherals Speciﬁcation but a Linux driver is available in

the Raspberry Pi Github Linux repository (bcm2835 smi.c in linux/drivers/misc).

9.1.3 Display Parallel Interface (DPI)

A standard parallel RGB (DPI) interface is available on bank 0 GPIOs. This up-to-24-bit parallel inter-

face can support a secondary display. Again this interface is not documented in the Broadcom Peripher-

als Speciﬁcation but documentation can be found here.

17 Release 2