4. Reset
Chip has 3 ways of reset:
◆ Power on reset;
◆ Low voltage reset;
◆ Watchdog overflow reset under normal working condition.
When any reset happens, all system registers reset to default condition, program stops executing and
PC is cleared. When finishing resetting, program executes from reset vector 0000H. TO and PD bit from
STATUS can provide information for system reset (see STATUS). User can control the route of the program
according to the status of PD and TO.
Any reset requires certain respond time. System provides completed reset procedures to make sure the
reset is processed normally.
4.1 Power on Reset
Power on reset is highly related to LVR. Power on process of the systems should be increasing, after
passing some time, the normal electrical level is then reached. The normal time series for power on is as
follows:
- Power on: system detects the voltage of the source to increase and wait for it to stabilize;
- System initialization: all system register set to initial value;
- Oscillator starts working: oscillator starts to provide system clock;
- Executing program: power on process ends, program starts to be executed.
4.2 External Reset
SC8F577x supports external reset, and RC3 can be configured as the reset port by CONFIG. Internal
weak pull-up of RC3 will enable when the external reset function is enabled. The chip will reset when
RC3 is pulled down.
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