Mbu - Ricoh Aficio 1515 Service Manual

9 March 2004
DRAM:
• The 8 MB of DRAM is shared as follows.
SAF memory
Working memory : 3 MB
Page memory
Memory back-up:
• A rechargeable battery backs up the SAF memory (DRAM) for one hour.

4.2.2 MBU

The flash ROM stores FCU firmware; the SRAM stores the system data and user
parameters. Since the system data and user parameters are stored on the MBU,
they are not changed if you replace the FCU.
ROM:
• 3MB flash ROMs for system software storage
2MB (16bit x 1MB) + 1MB (16bit x 512K)
SRAM:
• The 128 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
CN1 Switches the SRAM backup battery on or off.
: 2 MB
: 3 MB
Description
4-3
BOARDS