AAT2601 Analogic Corporation, AAT2601 Datasheet - Page 29

• Manufacturer Part Number: AAT2601
• Manufacturer: Analogic Corporation

I
and Programmability
Serial Interface
Many of the features of the AAT2601 can be controlled via
the I
ly used interface where it requires a master to initiate all
the communications with the slave devices. The I
tocol consists of 2 active wire SDA (serial data line) and
SCL (serial clock line). Both wires are open drain and
require an external pull up resistor to V
be used as V
SCL pin controls and references the I
is a bidirectional bus which allows both read and write
actions to take place, but the AAT2601 supports the write
protocol only. Since the protocol has a dedicated bit for
Read or Write access (R/W), when communicating with
AAT2601, this bit must be set to “0”.
2601.2008.01.1.0
2
C Serial Interface
SCL
SDA
2
C serial interface. The I
START
CC
). The SDA pin serves I/O function, and the
including R/W bit,
Chip Address = 0x98
MSB
1 0 0 1
Address
Chip
2
C serial interface is a wide-
1
0 0 0
LSB
2
C bus. I
ACK from slave
W
CC
ACK
(SYSOUT may
Figure 7: I
2
C protocol
w w w . a n a l o g i c t e c h . c o m
MSB
2
C pro-
Register
Address
2
C Timing Diagram.
Total Power Solution for Portable Applications
The timing diagram in Figure 7 depicts the transmission
protocol.
START and STOP Conditions
START and STOP conditions are always generated by the
master. Prior to initiating a START condition, both the
SDA and SCL pin are idle mode (idle mode is when there
is no activity on the bus and SDA and SCL are pulled to
V
START condition is defined to be when the master pulls
the SDA line low and after a short period pulls the SCL
line low. A START condition acts as a signal to all IC’s
that something is about to be transmitted on the BUS.
A STOP condition, also shown in Figure 7, is when the
master releases the bus and SCL changes from low to
high followed by SDA low to high transition. The master
does not issue an ACKNOWLEGE and releases the SCL
and SDA pins.
CC
via external resistor).
LSB
ACK from slave
ACK
MSB
PRODUCT DATASHEET
Data
As depicted in Figure 7, a
AAT2601178
LSB
ACK from slave
ACK
STOP
29