PCA9561 Ver la hoja de datos (PDF) - NXP Semiconductors.

Número de pieza

componentes Descripción

Lista de partido

PCA9561

Quad 6-bit multiplexed I2C-bus EEPROM DIP switch

NXP Semiconductors. 

NXP Semiconductors

PCA9561

Quad 6-bit multiplexed I2C-bus EEPROM DIP switch

7.2 System configuration

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 Figure 7).

SDA

SCL

MASTER

TRANSMITTER/

RECEIVER

SLAVE

RECEIVER

SLAVE

TRANSMITTER/

RECEIVER

MASTER

TRANSMITTER

MASTER

TRANSMITTER/

RECEIVER

I2C-BUS

MULTIPLEXER

SLAVE

Fig 7. System configuration

002aaa966

7.3 Acknowledge

The number of data bytes transferred between the START and the STOP conditions from

transmitter to receiver is not limited. Each byte of eight bits is followed by one

acknowledge bit. The acknowledge bit is a HIGH level put on the bus by the transmitter,

whereas the master generates an extra acknowledge related clock pulse.

A slave receiver which is addressed must generate an acknowledge after the reception of

each byte. Also a master must generate an acknowledge after the reception of each byte

that has been clocked out of the slave transmitter. The device that acknowledges has to

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 taken into account.

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.

data output

by transmitter

data output

by receiver

SCL from master

1

2

S

START

condition

Fig 8. Acknowledgement on the I2C-bus

not acknowledge

acknowledge

8

9

clock pulse for

acknowledgement

002aaa987

PCA9561

Product data sheet

All information provided in this document is subject to legal disclaimers.

Rev. 4 — 6 November 2012

© NXP B.V. 2012. All rights reserved.

10 of 26

Share Link: