PCF2131 datasheet(54/85 Pages) NXP

54 / 85 page

NXP Semiconductors

PCF2131

Nano-power highly accurate RTC with integrated quartz crystal

mbc622

SDA

SCL

STOP condition

SDA

SCL

START condition

Figure 30. Definition of START and STOP conditions

7.16.2.3 System configuration

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 PCF2131 can act as a slave transmitter and a slave receiver.

mba605

MASTER

TRANSMITTER

RECEIVER

SLAVE

RECEIVER

SLAVE

TRANSMITTER

RECEIVER

MASTER

TRANSMITTER

MASTER

TRANSMITTER

RECEIVER

SDA

SCL

Figure 31. System configuration

7.16.2.4 Acknowledge

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.

• A slave receiver which is addressed must generate an acknowledge after the reception of each byte.

• Also 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.

Acknowledgment on the I2C-bus is illustrated in Figure 32.

PCF2131

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

Product data sheet

Rev. 2.0 — 5 October 2023

54 / 85

PCF2131 Datasheet(PDF) 54 Page - NXP Semiconductors

PCF2131 Datasheet(HTML) 54 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85

Datasheet Download

Link URL