Pine64 Ox64 is a single-board computer with a RISC-V CPU that is Raspberry Pi Pico-sized and will be available in November for $6 and above.

A small single-board computer called the Pine64 Ox64 resembles the Raspberry Pi Pico in appearance. The Ox64 includes a dual-core RISC-V CPU, 64MB of inbuilt RAM, and support for up to 128Mb of flash storage in addition to a microSD card for extra storage, whereas the Raspberry Pi's small board is run by an RP2040 microcontroller.

It blurs the distinction between a microcontroller and an (extremely low-power) single-board PC and is anticipated to support RTOS and Linux. Prices for the board, which starts at $6 for an RTOS-ready device and $8 for a Linux-compatible one, are anticipated to be on sale in November.

The board also has two 20-pin GPIO headers for expansion, up to 16MB XSPI NOR flash, a MicroSD card slot, and a USB 2.0 OTG connector that supports a 2-lane MIPI CSI camera module. It is only 51 x 21 mm in size, or around the size of a Raspberry Pi Pico W.

CPU Architecture

• T_head C906 480MHz 64-bit RISC-V CPU

• Supports RISC-V RV64IMAFCV instruction architecture
• Five-stage single-issue sequentially executed pipeline
• Level-1 instruction and data cache of Harvard architecture, with a size of 32 KB and a cache line of 64B
• Sv39 memory management unit, realizing the conversion of virtual and real addresses and memory management
• jTLB that supports 128 entries
• Supports AXI 4.0 128-bit master interface
• Supports core local interrupt (CLINT) and platform-level interrupt controller (PLIC)
• With 80 external interrupt sources, 3 bits for configuring interrupt priority
• Supports BHT (8K) and BTB
• Compatible with RISC-V PMP, 8 configurable areas
• Supports hardware performance monitor (HPM) units

• T_head E907 320MHz 32-bit RISC-V CPU
• Supports RISC-V RV32IMAFCP instruction set
• Supports RISC-V 32-bit/16-bit mixed instruction set
• Supports RISC-V machine mode and user mode
• Thirty-two 32-bit integer general purpose registers (GPR) and thirty-two 32-bit/64-bit floating-point GPRs
• Integer (5-stage)/floating-point (7-stage), single-issue, sequentially executed pipeline
• Supports AXI 4.0 main device interface and AHB 5.0 peripheral interface
• 32K instruction cache, two-way set associative structure
• 16K data cache, two-way set associative structure

 System Memory

• Embedded 64MB PSRAM

Board Features

Network

• 2.4GHz 1T1R WiFi 802.11 b/g/n
• Bluetooth 5.2
• Zigbee
• 10/100Mbps Ethernet (optional, on expansion board)

Storage

• on-board 16Mb (2MB) or 128Mb (16MB) XSPI NOR flash memory
• microSD - supports SDHC and SDXC

Expansion Ports

• USB 2.0 OTG port
• 26 GPIO Pins, including SPI, I2C and UART functionality. Possible I2S and GMII expansion
• Dual lane MiPi CSI port, located at USB-C port, for camera module

Audio

• mic (optional, on camera module)
• speaker (optional, on camera module)

There are some additional details including the Ox64 schematic and BL808 datasheet + TRM in the wiki. There have been a number of Arm processors with built-in 64MB to 128MB memory from Allwinner and SigmaStar in recent years, so it's interesting to see Bouffalo Lab doing something similar with the BL808 RISC-V SoC.

Additionally, there is a 26-pin GPIO header that supports a MIPI CSI camera and has GPOIO, SPI, I2C, I2S, and UART. Pine64 says that the system has H.264 and MJPEG encoders, a JPEG decoder, and an audio subsystem and that it aims to provide 10/100 Ethernet, audio, and camera adapter boards in the future.

The board may not support Linux-based software at launch, but Pine64 has already started sending Ox64 boards to Linux developers in the hopes that they will be able to port the free and open-source operating system to run on the board. Pine64 says an RTOS SDK should be available in October, but getting Linux to run on the board will be a community project.

The board is made exclusively for RTOS and costs $6. It contains 16Mb of flash storage but no microSD card slot. Both versions are anticipated to be ready in November 2022; the $8 variant is intended for Linux development and features 128Mb of storage and a microSD card connector.