Rev. 1.20

15

November 25, 2015

HT9B92

Display RAM Page Write Operation

AfteraSTARTconditiontheslaveaddresswitha

writecontrolbitisplacedonthebusfollowedwith

thespecifieddisplayRAMRegisterAddressofwhich

thecontentsarewrittenintotheinternaladdress

pointer.Thedatatobewrittenintothememorywill

betransmittednext.Theinternaladdresspointerwill

beincrementedby1aftera4-bitdataisshiftedin.

Thentheacknowledgeclockpulsewillbereceived

afteran8-bitdataisshifted.Aftertheinternaladdress

pointreachesthemaximummemoryaddress,23H,

theaddresspointerwillberesetto00H.Itisstrongly

recommendedtowritethedisplayRAMdatafrom

address00Hto23HusingtheDisplayRAMPage

WriteOperation.

Command Summary

Thebit7denotedas“C”hereisthecontrolbitwhich

isusedtodeterminethatthenextbyteisthedisplay

RAMdataorcommandbyte.

C bit

Remark

0

Next byte is Display RAM data.

1

Next byte is command.

Slave Address

ACK

Write

S

0

1

1

1

1

1

0

0

ACK

Address n

ACK

Data byte

P

D7

D6

D5

D4

D3

D2

D1

D0

Data byte

D7

D6

D5

D4

D3

D2

D1

D0

ACK

ACK

Data byte

D7

D6

D5

D4

D3

D2

D1

D0

ACK

Register Address byte

A0

A1

A2

A3

A4

0

0

0

Display RAM Address Setting Command

ThiscommandisusedtodefinethestartaddressofthedisplayRAM.

Function

(MSB) Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 (LSB) Bit0

Note

Address Pointer

C

0

0

A4 A3 A2 A1

A0

Display RAM memory start address

Note: 1. The address ranges from 00H to 1FH.

2. It is strongly recommended to write the display RAM data from address 00H to 23H at one time.

3. Power on status: the address will be set to 00H.

4. If the programmed command is not defined, the function will not be affected.

Drive Mode Setting Command

ThiscommandisusedtocontroltheLCDbiasanddisplayon/off.

Function

(MSB) Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 (LSB) Bit0

Note

Bias and Display on/off setting

C

1

0

X

P3 P2

X

X

—

Note:

P2

Bias

0

1/3 bias (default)

1

1/2 bias

P3

LCD Display On/Off

0

Off (default)

1

On

● Power on status: The 1/3 bias drive mode is selected and the LCD display is switched off.

● If the programmed command is not defined, the function will not be affected.