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TSZ02201-0A0A2D300090-1-2

08.Sep.2015 Rev.004

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© 2013 ROHM Co., Ltd. All rights reserved.

TSZ22111･15･001

BU97950FUV

MAX 280 segments (SEG35×COM8)

○

Read Command Register and Transfer Method

BU97950 enters “Read mode” when R/W bit of Slave address is „1‟

During Read mode the command registers can be read.

The sequence for the command register read is shown below.

0111110

A 1

S

ADSET

Slave address

Command

0

R/W

A S

0111110

1

Slave address

R/W

A

Data

A P

The following register settings can be read in this mode.

Only one register setting can be read at once, after reading register setting, BU97950 will exit from read mode and wait

for slave address. If all register setting needs to be read, please make sequence for “REG1” and “REG2”, respectively.

Register

D7 D6 D5 D4 D3 D2 D1 D0

Address

REG1

0

0

P5

P4

P3

P2

P1

P0

23h

REG2

P7

P6

P5

P4

P3

P2

P1

P0

24h

REG1: P5 = Software reset condition

P4 to P0 = EVR setting

REG2: P7 to P6 = Frame Frequency (FR) setting

P5 to P4 = Power Save Mode (SR) setting

P3 = LCD drive waveform setting

P2 = Display ON/OFF setting

P1 = APON setting

P0 = APOFF setting

An example of the command register read sequence is shown below.

SCL

SDA

Slave Address (read)

A

P7

P6 P5 P4 P3 P2 P1 P0

A

S

P

○

LCD Driver Bias Circuit

This device generates LCD driving voltage with built in Buffer AMP.

And it can drive LCD at low power consumption.

*Line and frame inversion is set in DISCTL command.

Refer to the “LCD driving waveform” about each LCD driving waveform.

○

Reset initialize condition

Initial condition after Software Reset is as follows.

・

Display is OFF.

・

DDRAM address is initialized (DDRAM Data is not initialized).

Refer to Command Description about initialize value of register.

●

Command / Function List

Description List of Command / Function

Command

Function

1

Address set (ADSET)

DDRAM address setting (00h to 22h)

Command register address setting (23h, 24h)

2

EVR set (EVRSET)

EVR setting (0 to 31)

3

Display Control (DISCTL)

Frame Frequency, Power save mode setting

4

IC operation set (ICSET)

LCD drive mode, software reset, display on/off

5

All pixel Control (APCTL)

All pixel control during display ON