Single Board Computer (SBC)

The RAD750 processor requires as little as 2.5 V to operate because it has a relatively low transistor count of 10.4-million, which is far less than modern power hungry processors. An advantage of this low power consumption means that any system using this processor can operate on a few solar panels. RISC processors are therefore a better choice for use in spacecraft avionics.

A typical single board computer (SBC) shares many similarities with a standard PC architecture. For example, the PCI Bridge provides a version 2.1 compatible PCI bus. The bridge also provides a 16650 compatible UART for serial communications. There is also a JTAG interface facility for firmware programming and diagnostic operations.

Since hard disk drives cannot operate in space, a SUROM chip stores the operating system files. The RAD750 can access the SUROM chip directly and via the PCI Bridge for added flexibility. The SUROM provides 256 KB of electrically erasable programmable read-only memory (EEPROM) for storing the initial operating system and boot loader.

The SBC also has 128 KB of radiation hardened SDRAM, providing SEU error correction.

The oscillator frequency is 33 MHz to provide timing for the PCI Bridge as well as the real time clock (RTC). This speed allows the RAD750 to operate at a maximum speed of 133 MHz, consuming 10 W of electrical power when awake, and 1.9 W in sleep mode.

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