HT46C22 datasheet(25/46 Pages) HOLTEK

25 / 46 page

HT46R22/HT46C22

Rev. 1.10

October 2, 2002

Options

The following shows ten kinds of options in the microcontroller. ALL the options must be defined to ensure proper sys-

tem function.

No.

Options

OSC type selection.

This option is to decide if an RC or crystal oscillator is chosen as system clock.

WDT source selection.

There are three types of selection: On-chip RC oscillator, instruction clock or disable the WDT.

CLRWDT times selection.

This option defines how to clear the WDT by instruction.

²One time² means that the CLR WDT instruction can

clear the WDT.

²Two times² means only if both of the CLR WDT1 and CLR WDT2 instructions have been exe-

cuted, then WDT can be cleared.

Wake-up selection.

This option defines the wake-up function activity. External I/O pins (PA only) all have the capability to wake-up

the chip from a HALT.

Pull-high selection.

This option is to decide whether a pull-high resistance is visible or not in the input mode of the I/O ports.

PA0~PA7, can be independently selected.

PFD selection: PA3: Level output or PFD output

PWM selection: (7+1) or (6+2) mode

PD0: Level output or PWM output

WDT time-out period selection.

There are four types of selection: WDT clock source divided by 2

12,213,214 and 215

Low voltage reset selection: Enable or disable LVR function.

2C BUS function: Enable or disable

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