Nokia 8260 서비스 매뉴얼

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NSW-4 
System Module SE2L
PAMS Technical Documentation
Page  19
Issue 1  08/00
 Nokia Mobile Phones Ltd.
has been started once. The SLCLK output is enabled only when the
baseband parts are powered up.
After the sleep periods, when the VCXO is restarted (by RFCEN), MAD
takes care that the clock is not used before it is properly settled. MAD out-
put RFCSETTLED prevents COBBA from using the clock during the set-
tling time (RFCSETTLED rises later than RFCEN), as well MAD internally
inhibits DSP and MCU during the same time. This settling time can be
programmed before going to sleep mode, and the sleep clock is used for
measuring the time.
Resets
Power–up reset
CCONT gives the power–up reset (PURX) to MAD and COBBA. Also dis-
play is reset via MAD output pin. During this reset the VCXO clock has
enough time to settle so that it can be used as the system clock after
reset.
Other reset
COBBA can be also internally reset; there are two internal reset bits in
COBBA  registers which can be written by MAD.
LCD reset is possible also by by MCU SW, because the control pin pin is
controlled by MCU.
There are also MAD internal reset possibilities
 – MCU can reset system logic parts
 – MCU can reset DSP
 – SW–watchdog can reset the whole MAD