pca8885 NXP Semiconductors, pca8885 Datasheet - Page 20

• Manufacturer Part Number: pca8885
• Description: Capacitive 8-channel Proximity Switch With Auto-calibration And Very Low Power Consumption
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCA8885
Objective data sheet
13.2 System configuration
13.3 Acknowledge
A device generating a message is a transmitter; a device receiving a message is the
receiver. The device that controls the message is the master; and the devices which are
controlled by the master are the slaves. The system configuration is shown in
The number of data bytes transferred between the START and STOP conditions from
transmitter to receiver is unlimited. Each byte of 8 bits is followed by an acknowledge
cycle.
Acknowledgement on the I
Fig 11. System configuration
Fig 12. Acknowledgement on the I
•
•
•
•
A slave receiver, which is addressed, must generate an acknowledge after the
reception of each byte.
A master receiver must generate an acknowledge after the reception of each byte that
has been clocked out of the slave transmitter.
The device that acknowledges must pull-down the SDA line during the acknowledge
clock pulse, so that the SDA line is stable LOW during the HIGH period of the
acknowledge related clock pulse (set-up and hold times must be considered).
A master receiver must signal an end of data to the transmitter by not generating an
acknowledge on the last byte that has been clocked out of the slave. In this event, the
transmitter must leave the data line HIGH to enable the master to generate a STOP
condition.
SCL
SDA
by transmitter
data output
by receiver
data output
TRANSMITTER/
SCL from
RECEIVER
master
MASTER
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condition
START
Rev. 1 — 24 November 2011
S
Capacitive 8-channel proximity switch with auto-calibration
RECEIVER
2
C-bus is shown in
SLAVE
1
2
C-bus
TRANSMITTER/
RECEIVER
SLAVE
Figure
2
12.
TRANSMITTER
MASTER
not acknowledge
acknowledge
8
acknowledgement
clock pulse for
PCA8885
TRANSMITTER/
© NXP B.V. 2011. All rights reserved.
RECEIVER
MASTER
9
mbc602
Figure
mga807
20 of 43
11.