EM78871H Ver la hoja de datos (PDF) - ELAN Microelectronics

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componentes Descripción

Fabricante

EM78871H

8-BIT MICRO-CONTROLLER

ELAN Microelectronics 

EM78871

8-bit Micro-controller

1 select SEG72 ~ SEG75 output for LCD SEGMENT output.

Bit 3 (P9SH) : Switch high nibble I/O PORT9 or LCD segment output for share pins SEGxx/P9x pins

0 select normal P94 ~ P97 for high nibble PORT9

1 select SEG76 ~ SEG79 output for LCD SEGMENT output.*Bit 4:general register

Bit 4 (CWPWR) : Power control of Call Waiting circuit

1/0 enable circuit /disable circuit

Bit 5~Bit 6(IOC55~IOC57) : PORT5 I/O direction control registers.

0 put the relative I/O pin as output

1 put the relative I/O pin into high impedance

PAGE1 (Key tone control, CDAS, LCD bias control)

7

6

5

4

3

KT1

KT0

KTS

CDAS

BIAS3

Bit 0~Bit 3(BIAS0~BIAS3) : LCD operation voltage selection

V1 = VDD * (5 - n/15)/5

2

BIAS2

1

BIAS1

0

BIAS0

(BIAS3 to BIAS0)

0000

0001

0010

0011

0100

:

1101

1110

1111

V1 voltage

Example (VDD=5V)

VDD * (5-0/15)/5 5V

VDD * (5-1/15)/5 4.93V

VDD * (5-2/15)/5 4.86V

VDD * (5-3/15)/5 4.80V

VDD * (5-4/15)/5 4.73V

:

:

VDD * (5-13/15)/5 4.13V

VDD * (5-14/15)/5 4.07V

VDD * (5-15/15)/5 4.0V

BIAS

MUX

VC1 ~ VC5

generator

LCD driver

for

COM and SEG

COMs

SEGs

4

BIAS3 to BIAS0

VC1 ~ VC5

Fig.18 The relation between bias and V1 to V5

Fig.19a LCD waveform (1/4 bias) for 1/8 duty, 1/9 duty, 1/16 duty

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* This specification is subject to be changed without notice. 30

8/23/04 (V1.5)

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