LSI

LS3103

2

Functional Description

1. RC Oscillator /Crystal

The LS3103 can use either a crystal oscillator or RC oscillator to provide the internal timing by

mask option.

2. Program ROM

The LSI3103 has internal 1Kx12 bit ROM providing simple operation. It has four internal stack.

3. Interrupt Control

The LSI3103 has 5 different sources of interrupt, namely, POWERUP, F4HZ, F16HZA, F16HZS

and F1HZ. The starting address of the interrupt are as follow :

Interrupt

Address

POWERUP

0x3ff

F1HZ

0x3fe

F4HZ

0x3fc

F16HZA

0x3f8

F16HZS

0x3f1

The system generates 16 interrupts for F16HZS in one second but only 11 interrupts for F16HZA.

The other 5 interrupts goes to F4HZ (4) and F1HZ (1) interrupts.

3. RAM

The system has 73x4bit of program RAM with IO address as follows.

Address

Description

Initialize

0-0fH

RAM

undefined

10H-1fH

Display RAM

undefined

20-2fH

RAM

undefined

30H

rptrl

undefined

31H

rptrh

undefined

32H

rptr1

undefined

33H

Beep Control

0

34H-3fH

RAM

Undefined

54H-56H

Display RAM

Undefined

58H-5AH

Display RAM

Undefined

5CH-5EH

Display RAM

Undefined

73H

IOX Register

0

Address 31H:30H forms a 8 bit address for indirect read/write operation.

Address 32H:30H forms a 8 bit address for indirect read/write operation.