HT46R23

Rev. 1.30

25

August 17, 2001

ROM code option

The following shows ten kinds of ROM code option in the HT46R23. ALL the ROM code options must be defined to en-

sure proper system function.

No.

ROM Code Option

1

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

2

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

WDT.

3

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 in-

structions have been executed, then WDT can be cleared.

4

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.

5

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.

6

PFD selection:

PA3: level output or PFD output

7

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

PD0: level output or PWM0 output

PD1: level output or PWM1 output

8

9

Low voltage detector selection: Enable or disable LVD function.

10 I