Comparison with Raspberry Pi Compute Module 4
Differences are highlighted in bold text.
For Raspberry Pi Compute Module 5, see Libre Computer Solitude Compute Module and Alta Compute Module on CM5 IO
Highlights
- PCM in/out/sync/clock in place of USB 3 TX/RX, USB 3 and PCIe are muxed
- SDIO in place of HDMI 1, No Wireless on Module
- Simultaneous eMMC/SD Operation with SD Card Detect
- ARC (Alta) / eARC (Solitude) Pins (not on CM4 IO)
- Lineout Audio Pins (not on CM4 IO)
- PCIe Power and Wake Control
- SPI NOR/NAND Pins (not on CM5 IO)
- No CSI 0, CSI 1 is 2L on Solitude
- Low Power States Capable
Diagrams
Raspberry Pi Compute Module 4 Connector B
Libre Computer Cottonwood Compute Module
- 1, 3, 5 USB OTG with ID
- 9 PCIe Reset Active Low
- 11 VBUS_EN / Composite Video for CM5 Compatibility
- 15, 17, 21, 23, 27, 31, 33, 35, 39, 41 MIPI CSI 0 4 Lane
- 43, 45, 47,49 HDMI 1 HPD, I2C, CEC
- 51, 53 HDMI 0 HPD, CEC
- 57, 59 PCM CLK/SYNC, MIPI DSI0 D0 on CM4 IO
- 63, 65 USB 2 for CM5 Compatibility, MIPI DSI0 D1 on CM4 IO
- 69, 71 PCM OUT/IN, MIPI DSI 0 CLK on CM4 IO
- 75, 77 MIPI DSI 1 D0
- 81, 83 MIPI DSI 1 D1
- 87, 89 MIPI DSI 1 CLK
- 93, 95 MIPI DSI 1 D2
- 99, 100 HDMI 0 I2C
- 96, 94 MIPI DSI 1 D3
- 90, 88 HDMI 0 CLK
- 84, 82 HDMI 0 TX0
- 78, 76 HDMI 0 TX1
- 72, 70 HDMI 0 TX2
- 66, 64 GPIOX_14/GPIOX_15, HDMI 1 CLK on CM4 IO
- 60, 58 SDIO D3/D2, HDMI 1 D0 on CM4 IO
- 54, 52 SDIO D1/D0, HDMI 1 D1 on CM4 IO
- 48, 46 SDIO CMD/CLK, HDMI 1 D2 on CM4 IO
- 42, 40 CSI 0 CLK B / HDMI0_RSVD, MIPI CSI 0 CLK on CM4 IO
- 36, 34 Stereo Right, MIPI CSI 0 D1 on CM4 IO
- 30, 28 Stereo Left, MIPI CSI 0 D0 on CM4 IO
- 24, 22 PCIe TX
- 18, 16 PCIe RX
- 12, 10 PCIe CLK
- 6, 4 PCIe Power / PCIE Wake, NC on CM4 IO
- 2 PCIe Non-Posted Request
Raspberry Pi Compute Module 4 Connector A
Libre Computer Cottonwood Compute Module
- 3, 5, 9, 11 Ethernet PHY MDI 3/2
- 15, 17 Ethernet LEDs
- 19 PWM for Fan for CM5 Compatibility, NC on CM4 IO
- 21 VDDEE LED Green, Activity LED on CM4 IO
- 25, 27, 29, 31 40P GPIO Header
- 35 ID I2C Clock, 40P GPIO Header
- 37, 39, 41 40P GPIO Header
- 45, 47, 49 40P GPIO Header
- 51, 55 40P GPIO Header
- 57, 61, 63, 67, 69 SD CLK, D3, D0, D1, D2 (Second MMC Channel, CM4 Lite)
- 73 SD Voltage Override, NC on CM4 IO (For SDIO IO Voltage Control)
- 75 SD Power On
- 77, 79, 81, 83, 85, 87 5V IN
- 89, 91 GPIOX_12 / GPIOX_13, WiFi Dis, BT Dis on CM4 IO
- 93 USB MaskROM Mode
- 95 VDDAO LED Red, Power LED on CM4 IO
- 97 GPIO / IR Input (Wake Capable), CSI_GPIO on CM4 IO
- 99 GLOBAL_EN
- 100 nEXTRST External Reset Active Low
- 96, 94 SARADC CH 3 / 2 (0 - 1.8V), Analog P0 / P1
- 92 GPIOX_7, RUN_PG
- 90, 88 AO_1V8
- 86, 84 AO_3V3
- 82, 80 I2C (3.3V), CSI 1 / DSI 1 I2C on CM4 IO
- 78 GPIOA_VIO (Sets the Voltage on GPIOA Bank), GPIO_VREF on CM4 IO
- 76 SD Detect, NC on CM4 IO
- 72, 70, 68, 64 SPI NOR Access, NC on CM4 IO
- 62 SD CMD
- 58, 56 I2C AO, 40P GPIO Header
- 54, 50, AO GPIO, 40P GPIO Header
- 48, 46, GPIOA, 40P GPIO Header
- 44, 40, 38 SPI B, 40P GPIO Header
- 36 ID I2C Data, 40P GPIO Header
- 34, 30, 28, 26, 24 GPIOA, 40P GPIO Header
- 20 SPI NOR Write Protect Active Low, EEPROM Write Protect Active Low
- 18, 16 UART TX / RX, SYNC Out / In
- 12, 10, 6, 4 Ethernet PHY MDI 0/1