SCINTIX P4 RISC-V module adapts ESP32-P4 to Raspberry Pi CM4/CM5 carrier form factor

RELOC has developed the SCINTIX P4, a compute module built around Espressif's ESP32-P4NRW32X microcontroller that adopts the 55 x 40mm physical dimensions and Hirose DF40C-100DP connector layout of Raspberry Pi's CM4 and CM5 modules. The design enables developers to drop the module into existing carrier boards for prototyping, though with significant functional differences: the ESP32-P4 runs bare-metal or RTOS firmware through Espressif's ESP-IDF framework rather than Linux, and lacks HDMI and PCIe capabilities found on Raspberry Pi Compute Modules.

The module integrates dual 32-bit RISC-V cores at up to 400MHz with AI extensions and FPU, a 2D Pixel Processing Accelerator, H.264/JPEG hardware codecs, 32MB PSRAM, and 32MB NOR flash. Wireless connectivity comes via an ESP32-C6 companion chip providing Wi-Fi 6, Bluetooth 5 LE, and 802.15.4 for Thread/Zigbee. Wired networking is handled by a Microchip KSZ8091RNACA 10/100Mbps Ethernet PHY. RELOC has tested compatibility with official Raspberry Pi CM4/CM5 IO Boards and select third-party carriers, with firmware examples and documentation published to GitHub and further hardware design files planned.

Module architecture and carrier compatibility

• ESP32-P4 core complex: Two 32-bit RISC-V application cores at up to 400MHz with AI instruction extensions and single-precision FPU, plus a separate low-power RISC-V core at up to 40MHz for auxiliary control tasks.
• Memory hierarchy: 768KB L2 memory, 32KB low-power SRAM, 8KB tightly coupled memory, with 32MB external PSRAM and 32MB NOR flash for program and data storage.
• Multimedia and acceleration: Integrated 2D Pixel Processing Accelerator, H.264 encoder/decoder, and JPEG codec for embedded HMI and display applications.
• Wireless architecture: ESP32-C6 companion microcontroller connected via 4-bit SDIO and UART, providing 2.4GHz Wi-Fi 6, Bluetooth 5 LE, and IEEE 802.15.4 for Thread/Zigbee mesh networking.
• Carrier compatibility constraints: 40 GPIO signals routed through CM4/CM5 connectors with 23 accessible via the 40-pin expansion header; standard Raspberry Pi I2C header pins 3 and 5 unconnected, requiring alternative GPIO assignment. HDMI and PCIe not supported.

Why it matters

The SCINTIX P4 illustrates growing momentum in RISC-V embedded modules that repurpose popular physical form factors to lower prototyping barriers, though the mismatch between Linux-oriented carrier board peripherals and microcontroller capabilities requires careful design consideration. For the open hardware community, RELOC's planned release of schematics, KiCad libraries, and mechanical models could provide a reference for ESP32-P4 integration, while the existing GitHub repository with ESP-IDF 6.0.1 examples offers immediate development entry points for embedded engineers working in the Espressif ecosystem.