MT9P001 Datasheet, PDF (19/48 Pages) ON Semiconductor – CMOS Digital Image Sensor

MT9P001: 1/2.5-Inch 5Mp Digital Image Sensor
Two-Wire Serial Interface Sample Write and Read Sequences
Two-Wire Serial Interface Sample Write and Read Sequences
16-Bit WRITE Sequence
A typical WRITE sequence for writing 16 bits to a register is shown in Figure 11. A start bit
given by the master, followed by the write address, starts the sequence. The image sensor
then gives an acknowledge bit and expects the register address to come first, followed by
the 16-bit data. After each 8-bit transfer, the image sensor sends an acknowledge bit. All
16 bits must be written before the register is updated. After 16 bits are transferred, the
register address is automatically incremented so that the next 16 bits are written to the
next register. The master stops writing by sending a start or stop bit.
Figure 11: Timing Diagram Showing a WRITE to Reg0x09 with the Value 0x0284
SCLK
SDATA
START
0xBA ADDR
ACK
Reg0x09
ACK
0000 0010
1000 0100
STOP
ACK
ACK
16-Bit READ Sequence
A typical READ sequence is shown in Figure 12. First the master has to write the register
address, as in a WRITE sequence. Then a start bit and the read address specifies that a
READ is about to happen from the register. The master then clocks out the register data 8
bits at a time. The master sends an acknowledge bit after each 8-bit transfer. The register
address is incremented after every 16 bits is transferred. The data transfer is stopped
when the master sends a no-acknowledge bit.
Figure 12: Timing Diagram Showing a READ from Reg0x09; Returned Value 0x0284
SCLK
SDATA
0xBA ADDR
START
ACK
Reg0x09
ACK START
0xBB ADDR
ACK
0000 0010
ACK
1000 0100
STOP
NACK
MT9P001_DS Rev. L 4/15 EN
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