Datasheet

MAX13335E/MAX13336E
Dual Automotive Differential Audio Receivers
with I
2
C Control and Diagnostics
12
See the Applications Information section for various
examples on how the diagnostic can be set up to detect
different events.
Applications Information
Serial Interface
Writing to the device using I
2
C requires that first the mas-
ter send a START condition (S) followed by the device’s
I
2
C address. After the address, the master sends the
address of the register that is to be programmed. The
master then ends communication by issuing a STOP con-
dition (P) to relinquish control of the bus, or a repeated
START condition (Sr) to communicate to another I
2
C
slave (Figure 2).
Bit Transfer
Each SCL rising edge transfers one data bit. The data
on SDA must remain stable during the high portion of the
SCL clock pulse (Figure 3). Changes in SDA while SCL
is high are read as control signals (see the START and
STOP Conditions section). When the serial interface is
inactive, SDA and SCL idle high.
START and STOP Conditions
A master device initiates communication by issuing a
START condition (S) which is a high-to-low transition on
SDA with SCL high. A START condition from the master
signals the beginning of a transmission to the device.
The master terminates transmission by a STOP condi-
tion (P) (see the Acknowledge Bit section). A STOP
condition is a low-to-high transition on SDA while SCL is
high (Figure 4). The STOP condition frees the bus. If a
repeated START condition (S
r
) is generated instead of a
STOP condition, the bus remains active. When a STOP
condition or incorrect slave ID is detected, the device
internally disconnects SCL from the serial interface until
the next START or repeated START condition, minimiz-
ing digital noise and feedthrough.
Figure 2. I
2
C Timing
Figure 3. Bit Transfer Figure 4. START/STOP Conditions
SDA
SCL
t
F
t
R
t
F
t
LOW
t
SU:DAT
t
HD:STA
t
SU:STO
t
SU:STA
t
HD:STA
t
HIGH
t
HD:DAT
t
SP
t
R
t
BUF
SPSrS
SDA
SCL
DATA LINE
STABLE;
DATA VALID
CHANGE OF
DATA ALLOWED
SDA
START
CONDITION
STOP
CONDITION
SCL