Samsung MSYS 5150, Service Manual

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Samsung Electronics 5-17
Circuit Description
5-1-4 Power Monitor (U35: KIA7045AP)
If 5V power to KIA7045F drops to b4.65V and
+4.35V (typically 4.5V), power failure will be indicated
and the output of KIA7045F will go ‘low’. This cause
the flash memory (U27M28) and KS32C6100 (U1) to
became active (‘low’=reset). The flash memory and
KS32C6100 reset causes the SCAN-IP connected to
/RST_OUT terminal, modem, print controller to be
reset. The output terminal of KIA7045AP is an open-
drain configuration, output through a 5.1K pull-up
resistor.
5-1-5 Watch Dog Output (/RSTO)
W atch dog timer is programmable counter in the
KS32C6100. As initial state is enable, set the state to be
disable. After system switches to initialize mode, set the
state to be enable. If the watch dog reset and power on,
according to default setting,
5-1-6 Memory
S U M M A RY
System memory consists of 2MB flash memory, 32KB
SRAM, 8MB DRAM. MASKROM is selected optional.
M E M O RY STRUCTURE
Flash memory and DRAM are selected by chip select
(/RCSO-1, /FMEM_CS, /RASO-1, /SCS, /CASO-3)
lines, and data is accessed by the units position of the
word.