BU21025GUL Datasheet, PDF (5/19 Pages) Rohm – 4-wire Resistive Touch Screen Controller

BU21025GUL
Datasheet
Command Byte
BU21025GUL has a command byte after the address byte. Upper 4 bits of the command byte select an operation code. And
lower 4 bits of the command byte select an operand. Effects of the operands are changed by the operation code.
BIT
NAME
Table 2. Command Byte
MSB
LSB
7
6
5
4
3
2
1
0
C3
C2
C1
C0
O3
O2
O1
O0
BIT 7-4 : C3-0
Operation code:
BIT 3-0 : O3-0
Operand:
C3 C2 C1 C0
0
0
0
0
0
0
0
1
0
0
1
0
0
0
1
1
0
1
0
0
0
1
0
1
0
1
1
0
0
1
1
1
1
0
0
0
1
0
0
1
1
0
1
0
1
0
1
1
1
1
0
0
1
1
0
1
1
1
1
0
1
1
1
1
It is select an operation of the command. Detail is shown in Table 3.
It has 3 types. The operand type is selected by the operation code. When the operation
code is not “0101” or “1011”, the option type is 0. When it is “1011”, the option type is 1.
When it is “0101” option type is 2. Detail is shown in Table 3 and 4.
Table 3. Operation Code Function
FUNCTION
AD-INPUT X-DRIVER
Set Power
Reserved
Measure AUX
Reserved
Set Power
Software Reset
Reserved
Reserved
Drive X
Drive Y
Drive Z
Setup
Measure X
Measure Y
Measure Z1
Measure Z2
OFF
-
AUX
-
OFF
OFF
-
-
OFF
OFF
OFF
Keep
YP
XP
YN
XP
OFF
-
OFF
-
OFF
OFF
-
-
ON
OFF
XN-ON
Keep
ON
OFF
XN-ON
XN-ON
Y-DRIVER
OFF
-
OFF
-
OFF
OFF
-
-
OFF
ON
YP-ON
Keep
OFF
ON
YP-ON
YP-ON
INT
POLARITY
H
-
H
-
H
H
-
-
L
L
L
Keep
L
L
L
L
OPERAND
TYPE
0
-
0
-
0
2
-
-
0
0
0
1
0
0
0
0
Set Power (0000, 0100)
This code is used for returning to a state for touch detection without A/D conversion after sending screen drive command.
After this command, A/D converted data is set to 0.
Software Reset (0101)
BU21025GUL resets an A/D converted data, setup settings, and state of analog blocks to the initial state. If BU21025GUL
receives this code during an A/D conversion, the A/D conversion is stopped.
Drive X (1000), Drive Y (1001), Drive Z (1010)
BU21025GUL starts driving screen voltage by each code. PD is not effective. So, Driving is continuous until reserving
another command that changes state of driving screen voltage.
Measure AUX (0010), Measure X (1100), Measure Y (1101), Measure Z1 (1110), Measure Z2 (1111)
BU21025GUL starts driving screen voltage and A/D conversion. A PD of operand set,state of BU21025GUL after A/D
conversion is finished.
Setup (1011)
The setup command has a special operand (type is 1). The operand has MAF and pull-up resistor settings. Detail is
shown in Table 4.
www.rohm.com
© 2012 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
5/15
TSZ02201-0Y2Y0F300050-1-2
7.AUG.2012 Rev.002