Chapter 2 - Working With The It4X00 Series; Serial Command Interface (I 2 C); Data Write Sequence; Data Read Sequence - Hand Held Products IT4000 Integration Manual

2
Working with the IT4X00 Series
Serial Command Interface (I
The imager on the IT4X00 Series engine uses an I
Note: The register address pointer does NOT automatically increment the register pointer.
Each write to a sequential register requires the sub address (register address) be written with one byte of data. Each read from
a register other than the register last accessed (read or write) must have the sub address set using a "no data" write sequence
followed by the actual read. Only one byte of data should be clocked out when performing this read.
Slave Read/Write Address:Write Slave address40 Hex

Data Write Sequence

The following is an example of an I

Data Read Sequence

2
An I C read consists of a two step process. The first step is a transmit in write mode of the slave address, the sub address and
then a termination (a no data write). The first step sets the register address pointer inside the imager in preparation for the read.
The second step is the actual read of the data from the register of interest.
The following example shows the two step address write/read sequence:
IMAGETEAM™ 4X00 Series Integration Manual
C)
2
2
C style interface to write and read the internal control registers.
Read Slave address41 Hex
2
C write to the IT4X00 Series sequence:
Start Slave Address (7) R/W Ack Sub Address
0
Master
(byte)
Start Start Slave Address (7) R/W Ack Sub Address Slave Address (7) R/W Ack Sub Address
0 0
Master Master
(byte) (byte)
Start Slave Address (7) R/W Ack
1
Master
(byte)
Ack Data
(Reg Add)
Slave Master Slave Master
(bit) (byte) (bit) (byte)
Ack Stop Ack Stop
(Reg Add) (Reg Add)
Slave Slave Master Master Slave Slave
(bit) (bit) (byte) (byte) (bit) (bit)
Data Ack Stop
Slave Slave Master
(bit) (byte) (bit)
Ack Stop
Slave
(bit)
2 - 1