21 December, 2001
BOARDS
4-3
Detailed
Descriptions
DRAM
•
The 8 MB of DRAM is shared as follows.
SAF memory
: 2 MB
Working memory : 2 MB
Page memory
: 4 MB
•
The SAF memory is backed up by a rechargeable battery.
Memory back-up
•
A rechargeable battery backs up the SAF memory (DRAM) for 1 hour.
Switches
Item
Description
SW1
Reset switch, to reboot the FCU board
4.2.2 MBU
On this board, the flash ROM contains the FCU firmware, and the SRAM contains
the system data and user parameters. Even if the FCU is changed, the system
data and user parameters are kept on the MBU board.
ROM
•
2 MB flash ROM (16 bits x 1 MB) for system software storage
SRAM
•
The 256 KB SRAM for system and user parameter storage is backed up by a
lithium battery.
Memory back-up
•
A lithium battery backs up the system parameters and programmed items in
the SRAM, in case the base copier's main switch is turned off.
Switches
Item
Description
SW1
Switches the SRAM backup battery on/off.