pca9546abs NXP Semiconductors, pca9546abs Datasheet - Page 8

• Manufacturer Part Number: pca9546abs
• Description: 4-channel I2c Switch With Reset
• Manufacturer: NXP Semiconductors

Philips Semiconductors
7. Characteristics of the I
PCA9546A_4
Product data sheet
7.1 Bit transfer
7.2 START and STOP conditions
7.3 System configuration
More Information can be found in Application Note AN262: PCA954X family of I
multiplexers and switches .
The I
lines are a serial data line (SDA) and a serial clock line (SCL). Both lines must be
connected to a positive supply via a pull-up resistor when connected to the output stages
of a device. Data transfer may be initiated only when the bus is not busy.
One data bit is transferred during each clock pulse. The data on the SDA line must remain
stable during the HIGH period of the clock pulse as changes in the data line at this time
will be interpreted as control signals (see
Both data and clock lines remain HIGH when the bus is not busy. A HIGH-to-LOW
transition of the data line while the clock is HIGH is defined as the START condition (S).
A LOW-to-HIGH transition of the data line while the clock is HIGH is defined as the STOP
condition (P) (see
A device generating a message is a ‘transmitter’, a device receiving is the ‘receiver’. The
device that controls the message is the ‘master’ and the devices which are controlled by
the master are the ‘slaves’ (see
Fig 8. Bit transfer
Fig 9. Definition of START and STOP conditions
2
C-bus is for 2-way, 2-line communication between different ICs or modules. The two
SDA
SCL
START condition
2
SDA
SCL
Figure
C-bus
S
Rev. 04 — 29 August 2006
9).
Figure
data valid
data line
stable;
10).
Figure
allowed
change
of data
8).
4-channel I
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
STOP condition
2
C-bus switch with reset
PCA9546A
mba607
P
mba608
2
C/SMBus
SDA
SCL
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