AK4183_08 Datasheet, PDF (10/18 Pages) Asahi Kasei Microsystems – I2C Touch Screen Controller

[AK4183]
[Address Byte]
The sequence of writing data is shown Figure 10. The address byte, which includes seven bits of slave address and one
bit of R/W bit, is sent after the START condition. If the transmitted slave address matches an address for one of the
device, the receiver who has been addressed pulls down the SDA line (acknowledge).
The most significant six bits of the slave address are fixed as “100100”. The next one bit is CAD0 (device address bit).
This bit identifies the specific device on the bus. The hard-wired input pin (CAD0 pin) sets CAD0 bit. The eighth bit
(LSB) of the address byte (R/W bit) defines whether the master requests a write or read operation. A “1” indicates that
the read operation is to be executed. A “0” indicates that the write operation is to be executed.
1
0
0
1
0
0 CAD0 R/W
(CAD0 should match with CAD0 pins)
Figure 8. Address Byte
[WRITE Operations]
The second byte that followed by address byte consists of the control command byte of the AK4183. The operational
mode is determined by control command. The bit format is MSB first and 8 bits width. Control command is described
in the Table 3. The AK4183 generates an acknowledge after each byte has been received. A control command transfer
is terminated by a STOP condition or Repeated Start condition generated by the master. Refer to the Table 3 in detail.
D7
D6
D5
D4
D3
D2
D1
D0
S
A2
A1
A0
X1
PD0
MODE
X2
Figure 9. Control Command Byte
SDA _{S Address}
Command
P
Figure 10. Single Write Transmission Sequence
[READ Operation]
The operation mode is determined by the write command just before read operation.
The AK4183 features two methods of read operation, single read operation and continuous read operation. The
continuous read operation is a series of single read operation. Each single read operation in continuous read operation
makes the AK4183 updated A/D conversion on each read operation. Write operation does not need to issue before each
read operations are executed.
The channel selection of the AK4183 defines by the control command just before READ operation. When the address
byte with R/W = “1” read operations are executed. A/D readout format is MSB first, 1byte or 2bytes width. Upper 8bits
are valid on 8-bit mode and upper 12 bits are valid, and lower 4 bits are filled with zero on 12-bit mode.
MS0500-E-01
10
2008/12