NSW-6
System Module SE2
PAMS Technical Documentation
Page 28
Issue 1 12/99
Nokia Mobile Phones Ltd.
with the charger connector signal. PWMOUT signal frequency is selected
to be 32 Hz, and the charger output voltage is controlled by adjusting the
PWMOUT signal pulse width. The charger switch in CHAPS is constantly
on in this case.
Watchdog
Both MAD and CCONT include a watchdog, and both use the 32 kHz
sleep clock. The watchdog in MAD is the primary one, and this is called
SW–watchdog. MCU has to update it regularly. If it is not updated, logic
inside MAD gives reset to MAD. After the reset, MCU can read an inter-
nal status bit to see the reason for reset, whether it was from MAD or
CCONT. The SW–watchdog delay can be set between 0 and 63 seconds
at 250 millisecond steps; and after power–up the default value is the max.
time.
CCONT
BATTERY
VCXO
MAD
COBBA
LCD–DRVR
VR1
VBB
SIO
MCU
LOGIC
VR6
32 kHz
SLCL
K
MAD must reset CCONT watchdog regularly. CCONT watchdog time can
be set through SIO between 0 and 63 seconds at 1 second steps. After
power–up the default value is 32 seconds. If watchdog elapses, CCONT
will cut off all supply voltages.
After total cut–off the phone can be re–started through any normal
power–up procedure.
Battery Overvoltage Protection
Output overvoltage protection is used to protect phone from damage. This
function is also used to define the protection cutoff voltage for different
battery types (Li or Ni). The power switch is immediately turned OFF if the
voltage in VOUT rises above the selected limit VLIM1 or VLIM2.
