User Manual

System Architecture
CPU
Motorola’s MC68331 processor is used as the main controller of the system. It runs at 16Mhz,
which is generated from an external 32.768Khz crystal. The CPU interfaces with flash memory,
SRAM, GPS Asic and other I/Os in the system. An internal watchdog timer is used to generate
the system reset.
Flash Memory
Flash ROM is used to store all the firmware and other information such as manufactures ID, user
code, and other permanent codes. The board layout can be configured to use 4Mbit or 8Mbit
Flash.
Flash Memory contains the following key components:
1. Boot block (OTAP capable in 96 and above firmware version)
2. Configuration data (IP addresses, device ID etc.)
3. GPS lookup tables.
4. Main program executable.
SRAM
SRAM is used to store all volatile and non-volatile data including PVT (Position, Velocity, Time)
points and retain the data through use of a small battery.