EM78P813

8-bit OTP Micro-controller

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* This specification is subject to change without notice.

12

2004/8/19

(V1.6)

64K Program ROM

Unused

256K byte

Data ROM

EM78P813

(EXSEL pin pull high)

MAX 2M Byte Expand ROM

(FLASH ROM)

128K word Program ROM

(PAGE0~PAGE127)

ExpandData ROM

Expand Data ROM start address

0

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

0

0

RF PAGE1

RF PAGE2

0

ROM

Address

0

ROM

Address

9

ROM

Address

17

b0

b0

b7

b7

IOCB

B7

Fig5(b) : EXSEL = 1, only external program are used.

How to set start address for expanding Data ROM?

EM78815 support maximum 2M Byte expanding data memory, but user must fix the start address of external

program at 0x00000 and set start address of expanding Data ROM by user. By this way, MCU will get data from external

memory if the data ROM is over 256K.

The width of an instruction is 13 bit and the data bus for external memory is 8bit, so an instruction will captured two

address size and the LSB address of start address at external ROM will be 0. Besides, EM78815 only support MAX 128K

program, so the start address of Data ROM will smaller than 256K-2 andA20, A19 and A18 will be 0 also. User only has to

according to write Data ROM address A17~A1 to IOCB PAGE2 bi7,RF PAGE3 and RF PAGE2.

EM78P813 writer pin

OTP writer PIN NAME

MASK ROM PIN NAME

P.S.

1.VDD

VDD,AVDD

2.VPP

/RESET

3.DINCK

P77

4.ACLK

P76

5.PGM

P75

6.OE

P74

7.DATA

P73

8.GND

VSS,AVSS,TEST

9.ROMSEL

P72

High : Data ROM

Low : Program ROM