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Wd report register - index 38h -14 – Acrosser AR-B1320 User Manual

Page 33

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A

A

R

R

-

-

B

B

1

1

3

3

2

2

0

0

U

U

s

s

e

e

r

r

s

s

G

G

u

u

i

i

d

d

e

e


3-14

3.15.2

WD REPORT REGISTER - INDEX 38H
This register is used to select the watchdog report when the watchdog times out.

Bit 7-4 Watchdog Timer Time-out Report Signal Select

0000

No output signal

0001 IRQ3

selected

0010 IRQ4

selected

0011 IRQ5

selected

0100 IRQ6

selected

0101 IRQ7

selected

0110 IRQ9

selected

0111 IRQ10

selected

1000 IRQ11

selected

1001 IRQ12

selected

1010 IRQ14

selected

1011 IRQ15

selected

1100 NMI

selected

1101

System reset selected

1110

No output signal

1111

No output signal

Bit 3-0

Other function. Please do not modify these bits.

Note 1):If you program the watchdog to generate an IRQ signal when it times out, you should initialize

the IRQ interrupt vector and enable the second interrupt controller (8259 PIC) in order to enable
the CPU to process this interrupt. An interrupt service routine is required too.


2) Before you initial the interrupt vector of the IRQ and enable the PIC, please enable the

watchdog timer previously, otherwise the watchdog timer will generate an interrupt at the time the
watchdog timer is enabled.

3.15.3

WD TIMER COUNTER(24 BITS) - INDEX 39H, 3AH, AND 3BH
These registers are used to set the desired counter for the watchdog to count down. The time
base of each count is 30.5μsec.

INDEX 3Bh

3Ah 39h

Data Bit

D7…D0

D7…D0

D7…D0

24-bit Counter

D23…D16

D15…D8

D7…D0


For example:

INDEX

3Bh 3Ah 39h

Watchdog Timer

00h 00h 01h

30.5 μsec

00h 00h 02h

61.0 μsec

00h 01h 00h

7.8

m

sec

00h 02h 00h

15.6

m

sec

01h 00h 00h

2

sec

02h 00h 00h

4

sec

0FFh 0FFh 0FFh

512 sec