GR716B - LEON3FT Microcontroller

The GR716B is a radiation-hardened microcontroller featuring the fault-tolerant LEON3 SPARC V8 processor. Based on the GR716A design, the GR716B has been developed to provide a more advanced SoC with higher computational performance and excellent communication interfaces.

The GR716B is currently under development and prototypes will be available in 2023.


  • System frequency up-to 100 MHz
  • SpaceWire links up-to 200 Mbps
  • CQFP132 hermetically sealed ceramic package
  • Total Ionizing Dose (TID) up to 300 krad (Si)
  • Single-Event Latch-up Immunity (SEL) to LETTH > 118 MeV-cm2mg
  • Single-Event Upset (SEU) below TBD errors per device and day in space environment
  • Support for single 3.3V supply



  • Fault-tolerant  LEON3 SPARC V8 processor
    • 16-bit instruction set: LEON-REX for improved code density
    • Double precision IEEE-754 pipelined floating point unit
    • Memory protection units
    • Deterministic software execution and non-intrusive debugging
    • Fast context switching (PWRPSR, AWP, register partitioning, interrupt mapping, SVT, MVT) 
    • Interrupt zero jitter delay
  • 2x Real Time Accelerator (RTA)
    • Offload the main LEON3 for simple tasks
  • Non-intrusive advanced on-chip debug support unit
  • External EDAC protected 8-bit PROM/SRAM memory
  • SPI memory protected by EDAC and dual memory redundancy
  • Power-on-Reset and Brown-out-detection
  • FPGA supervisor for FPGA programming and scrubbing
    • Can target Xilinx Virtex5 and Kintex UltraScale
  • Programmable PWM interface with Analog/Digital Voltage
    control and motor control loop support
  • Programmable pulse-width-modulation DAC
  • On-chip Boot ROM for low-level initialization and optional self-testing, standby and application loading
  • Remote boot through SpaceWire RMAP, CANOpen, SPI slave or UART
  • Enhanced DMA controller
  • Timers with Watchdog


  • 2-Port SpaceWire Router with time distribution support, 200 Mbps max bitrate
    • LVDS with extended common-mode,  Cold-Spare and Fail-Safe support
  • 10/100 Mbit/s Ethernet
  • MIL-STD-1553B interface
  • CAN-FD controller interface with CANopen support for remote boot
  • PacketWire with CRC acceleration support
  • Programmable Enhanced PWM with analog/digital voltage control loop support
  • SPI with SPI-for-Space protocols
  • UARTs, I2C, GPIO
  • Mixed General purpose inputs and outputs

Integrated Analog functions

  • 4x Rad-Hard ADC 13bits resolution @ 500Ksps, 8 differential or 16 single-ended channels
  • Rad-Hard DAC 12bits @ 3Msps, 4 channels
  • 20x Analogue voltage comparator
  • Rad Hard PLL
  • Crystal Oscillator
  • Power-on-Reset and Brown-out-detection
  • 1.8V and 3.3V voltage monitors
  • LVDS transceivers with build-in reference
  • Rad Hardened voltage and current reference
  • Rad Hardened Low-drop regulators for single supply support
  • Rad Hardened external voltage references
  • Temperature sensor, Integrated PLL
  • On-chip regulator for 3.3V single supply

 Software Development Environment (SDE)

We provide compiler toolchains and development tools with GR716B-specific support such as the GR716B BSPs, GRMON support and simulator CPU/IO models. The Bare-metal environment is free and open-source. The GR716-MINI board can be evaluated using the free GRMON3 evaluation version.

Our SDE for the GR716 consists of the following software components:

Memory support

  • 192KiB EDAC protected tightly coupled memory with single cycle access from processor and ATOMIC bit operations
  • Embedded ROM with bootloader for initializing and remote access
  • Dedicated SPI Memory interface with boot ROM capability
  • 8-bit SRAM/ROM I/F with support up to 16MiB ROM and 256MiB SRAM
  • Scrubber with programmable scrub rate for all embedded memories and external PROM/SRAM and SPI memories
  • Redundant boot memory (PROM/SRAM/SPI/I2C/NVRAM)
  • Application software container for checking software integrity using CRC
  • Boot from internal SRAM, external PROM/FLASH/SRAM/SPI/I2C memory

The GR716B microcontroller is currently in the development phase and there is no guarantee that a flight part will be developed, qualified or sold.


Document Link
GR716B Data Sheet and User’s Manual GR716B-DS-UM (December 2022)