Service manual

Samsung Electronics 5-11
As for SMARTJET there are 2 power resets of primary reset(/F-POR) and secondary reset(/POR) and also
reset by watchdog timer (/RSTO). Primary reset is used to initialize flash memory when the system is turned
on, while secondary reset is used to initialize the whole system by initializing MFP controller (KS32C6200)
after primary reset. Primary reset makes flash memory wait in READ mode to fetch program codes, and sec-
ondary reset makes the main controller (KS53C6200) wake up and initialize external peripherals to operate
the system. Fig.5-1-10 is Power Reset Timing Diagram.
5-1-2-10. RESET CIRCUIT
supply
Voltage
/F-POR
/POR
PnRST
Internal Reset
256 MCLK
Reset filter
65 MCLK
ROM Access
(internal)
Reset
Fig.5-1-10 POWER RESET TIMING DIAGRAM