EM78P813 datasheet(11/65 Pages) EMC

11 / 65 page

EM78815 mode (must set RE page2 bit2 ~ bit4 = 1)

30us

Key scan pin(P8,P9)

VDD

GND

Fig.4(b) : EM78815 mode Key scan signal(share with IO pin)

EXSEL pin : 0/1

On-Chip program ROM used/unused switch(EM78815 mode only).

EM78P813 support MAX 128K Program . User can port program to both 64K EM78P813 on_chip ROM and

64K expand ROM .

User also can ignore 64K EM78P813 on_chip ROM and porting all programs to a external

128K ROM. Using this function, user can upgrade program or download new function easily.

EM78P813 provide Data ROM expand function. When user access data which address is over 256K, external

ROM will be load. User must set expand start address of Data ROM to RF PAGE1, PAGE2 and IOCB PAGE1. A

diagram of expand function is as below.

64K Program ROM

(PAGE0 ~ PAGE 63)

256K byte

Data ROM

EM78P813

(EXSEL pin go low)

MAX 2M Byte Expand ROM

(FLASH ROM)

64K word Program ROM

(PAGE64~PAGE127)

ExpandData ROM

Expand Data ROM start address

RF PAGE1

RF PAGE2

ROM

Address

ROM

Address

ROM

Address

IOCB

Fig5(a) : EXSEL = 0,both internal and external program are used.

EM78P813 Datasheet(PDF) 11 Page - ELAN Microelectronics Corp