Datasheet

Table Of Contents
PDF: 09005aef8202ec2e/Source: 09005aef8202ebf7 Micron Technology, Inc., reserves the right to change products or specifications without notice.
MT9D111__7_REV5.fm - Rev. B 2/06 EN
182 ©2004 Micron Technology, Inc. All rights reserved.
MT9D111 - 1/3.2-Inch 2-Megapixel SOC Digital Image Sensor
Appendix A: Two-Wire Serial Register Interface
Micron Confidential and Proprietary
Acknowledge Bit
The master generates the acknowledge clock pulse. The transmitter (which is the master
when writing, or the slave when reading) releases the data line, and the receiver indi-
cates an acknowledge bit by pulling the data line low during the acknowledge clock
pulse.
No-Acknowledge Bit
The no-acknowledge bit is generated when the data line is not pulled down by the
receiver during the acknowledge clock pulse. A no-acknowledge bit is used to terminate
a read sequence.
Page Register
The MT9D111 two-wire serial interface and its associated protocols support an address
space of 256 16-bit locations. This address space is extended by a 3-bit page prefix, and
controlled through accesses to R0xF0:0.
The paging mechanism is intended to allow access to other sets of registers when the
sensor is embedded as part of a more complex integrated subsystem, for example, in an
SOC. All registers within the sensor core are accessible on page 0 (the default page).
Sample Write and Read Sequences
16-Bit Write Sequence
A typical write sequence for writing 16 bits to a register is shown in Figure 52. A start bit
given by the master starts the sequence, followed by the write address. The image sensor
then sends 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 52: WRITE Timing to R0x09:0—Value 0x0284
SCLK
S
DATA
0xBA Address
Start
Stop
ACK
ACK ACK
ACK
Reg0x09 0000 0010 1000 0100