BU21049GUL

TSZ02201-0Y1Y0F300010-1-2

© 2011 ROHM Co., Ltd. All rights reserved.

31.JAN.2012 Rev.001

www.rohm.co

TSZ22111・15・001

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Datasheet

Datasheet

●Host interface specification

The BU21049GUL operates as I2C slave device. The host processor transmit address byte after start condition when start

communication with the BU21049GUL. In case of operate convert function or write to register of the BU21049GUL, the host

processor transmit command byte after receive acknowledge of address byte. Communication with the BU21049GUL is

end when receive stop condition.

Address byte

Slave address for 2-wire interface is placed in the upper 7-bit of address byte and the last bit is READ/WRITE.

The upper 6-bit of slave address is fixed to “100000”, and the last bit of slave address is selected by “AD0” input.

Serial interface slave address byte

MSB

D7

D6

D5

D4

D3

D2

D1

LSB

D0

10

0000

A0

R/W

Bit D1: A0

Slave address bit0 (AD0)

Bit D0: R/W

1=read (reading data)

0=write (writing data)

Command byte

The BU21049GUL operates depend on command byte. The host processor set CID (D7) to 1 when perform convert

function or set CID(D7) to 0 when perform register access..

Serial interface Command byte 1(CID=1)

MSB

D7

D6

D5

D4

D3

D2

D1

LSB

D0

1CMSK

PDM

STP

CF

Bit D7: Command Byte ID

1= Command Byte 1(start conversion function according to CF(Bit D6-D3)

Bits D6-D4: CF

Convert function select as detailed the below.

BU21049GUL Convert function List

CF

Description

0x0

Touch screen scan function: X, Y, Z1 and Z2 coordinates and converted.

0x1

NOP

0x2

Auxiliary input converted.

0x3

Reserved

0x4

Free scan function: Drivers status and input of A/D assignment by Host.

0x5

Calibration: Paramters which used dual touch detection calibrated.

0x6

NOP

0x7

NOP

0x8

X+, X- drivers status.

0x9

Y+, Y- drivers status.

0xA Y+, X- drivers status.

0xB NOP

0xC

Touch screen scan function: X coordinate converted.

0xD

Touch screen scan function: Y coordinate converted.

0xE Touch screen scan function: Z1 and Z2 coordinates converted.

0xF

Reserved