PCF2129AT/2,518 NXP Semiconductors, PCF2129AT/2,518 Datasheet - Page 47

• Manufacturer Part Number: PCF2129AT/2,518
• Description: Real Time Clock
• Manufacturer: NXP Semiconductors
• Series: PCF2129r

Specifications of PCF2129AT/2,518

• Rohs: yes
• Function: Clock, Calendar, Alarm, Watchdog, Timestamp
• Rtc Bus Interface: I2C, SPI
• Date Format: Binary
• Time Format: Binary
• Supply Voltage - Max: 4.2 V
• Supply Voltage - Min: 1.2 V
• Maximum Operating Temperature: + 60 C
• Minimum Operating Temperature: - 15 C
• Mounting Style: SMD/SMT
• Package / Case: SOP-20
• Battery Backup Switching: Yes
• Factory Pack Quantity: 2000

NXP Semiconductors
PCF2129AT
Product data sheet
Fig 29. SPI-bus write example
Fig 30. SPI-bus read example
SDA/CE
SDA/CE
address
address
counter
counter
In this example, the Seconds register is set to 45 seconds and the Minutes register to 10 minutes.
SDO
In this example, the registers Months and Years are read. The pins SDI and SDO are not connected together. For this
configuration, it is important that pin SDI is never left floating. It must always be driven either HIGH or LOW. If pin SDI is left
open, high I
SCL
SCL
SDI
SDI
xx
xx
R/W
R/W
b7
b7
0
1
b6
b6
DD
0
0
SA
SA
currents may result.
Table 50.
b5
b5
Bit
6 to 5
4 to 0
7
1
1
b4
b4
0
0
b3
b3
0
1
addr 03h
addr 08h
Symbol
R/W
SA
RA
Command byte definition
b2
b2
0
0
b1
b1
1
0
All information provided in this document is subject to legal disclaimers.
b0
b0
1
0
b7
b7
03
08
Rev. 5 — 12 February 2013
0
0
b6
b6
1
0
seconds data 45
months data 11
b5
b5
0
0
Value
0
1
01
00h to 1Bh register address
b4
b4
0
1
b3
b3
0
0
BCD
BCD
b2
b2
1
0
Description
data read or write selection
subaddress;
b1
b1
0
0
write data
read data
other codes will cause the device to ignore data
transfer
Integrated RTC, TCXO and quartz crystal
b0
b0
1
1
b7
b7
04
09
0
0
b6
b6
0
0
minutes data 10
b5
b5
years data 06
0
0
b4
b4
1
0
PCF2129AT
b3
b3
0
0
BCD
BCD
b2
b2
0
1
© NXP B.V. 2013. All rights reserved.
b1
b1
0
1
b0
001aaj348
b0
001aaj349
0
0
05
0A
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