18

* This specification are subject to be changed without notice.

EM73880

EM73880

EM73880

EM73880

EM73880

4-BIT MICRO-CONTROLLER FOR LCD PRODUCT

4-BIT MICRO-CONTROLLER FOR LCD PRODUCT

4-BIT MICRO-CONTROLLER FOR LCD PRODUCT

4-BIT MICRO-CONTROLLER FOR LCD PRODUCT

4-BIT MICRO-CONTROLLER FOR LCD PRODUCT

11.30.2001

Preliminary

Preliminary

Preliminary

Preliminary

Preliminary

For the pulse width measurement mode, the counter only incresed by the rising edge of internal pulse rate as

external timer/counter input (P8.1/TRGB, P8.3/TRGA), interrupt request will be generated as soon as

timer/counter count overflow.

Internal pulse

TimerB(TimerA) value

n

n+1

n+2

n+3

n+4

n+5

P8.1/TRGB(P8.3/TRGA)

LDIA #1100b;

OUTA P28; Enable timerA with pulse width measurement mode.

HIGH SPEED TIMER/COUNTER

HIGH SPEED TIMER/COUNTER

HIGH SPEED TIMER/COUNTER

HIGH SPEED TIMER/COUNTER

HIGH SPEED TIMER/COUNTER

8-bit high speed timer/counter (HTC) supports three special functions : auto load timer, melody output

and pulse width measurement modes. The HTC is available for the NORMAL and SLOW operation mode.

The HTC can be set initial value and send counter value to counter registers (P11 and P10), P31 is the

command port for HTC, user can choose different operation mode and different internal clockrate by setting

the port. The timer/counter increase one at the rising edge of internal pulse. The HTC can generate an overflow

interrupt (HTCI) when it overflows.

P31 is the command register of the 8-bit high speed timer/counter.

P31

3

210

Initial value : 0000

HTMS

HIPS

HTMS

Mode selection

HIPS

Clock rate selection

NORMAL mode

SLOW mode

0 0

Stop

0 0

0 1

Event counter mode

0 1

1 0

Auto load timer mode

1 0

Reserved

1 1

Pulse width measurement mode

1 1

Reserved

* CLK=4.6MHz

P11 and P10 are the counter registers of the 8-bit high speed timer/counter. P10 is the lower nibble register

and P11 is the higher nibble register. (HT is the value of counter registers.)

P11

3

210

P10

3

210

Initial value : 0000 0000 (HT)

Higher nibble register

Lower nibble register

P31(3,2)

P4.1/TRGH

8-bit binary counter

P31(1,0)

P11

÷2

P10

XIN

Input data

Data bus

Reload

Overflow

HTCI interrupt

Timer/counter B