PCF2127AT/2Y NXP Semiconductors, PCF2127AT/2Y Datasheet - Page 60

• Manufacturer Part Number: PCF2127AT/2Y
• Description: Real Time Clock Integrated RTC TCXO quartz crystal
• Manufacturer: NXP Semiconductors
• Series: PCF2127ATr

Specifications of PCF2127AT/2Y

• Rohs: yes
• Function: Clock, Calendar, Temperature
• Rtc Bus Interface: I2C
• Date Format: DW
• Time Format: HH
• Rtc Memory Size: 512 B
• Supply Voltage - Max: 4.2 V
• Supply Voltage - Min: 1.8 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Package / Case: SOT-163-1
• Battery Backup Switching: Yes

NXP Semiconductors
PCF2127AT
Product data sheet
Fig 43. Bus protocol, reading from registers
S
S
1
1
9.2.5 I
0
0
slave address
slave address
1
1
After a start condition, a valid hardware address has to be sent to a PCF2127AT device.
The appropriate I
is shown in
Table 60.
The R/W bit defines the direction of the following single or multiple byte data transfer (read
is logic 1, write is logic 0).
For the format and the timing of the START condition (S), the STOP condition (P), and the
acknowledge bit (A) refer to the I
characteristics table
either a STOP condition or the START condition of the next data transfer.
Bit
2
Fig 42. Bus protocol, writing to registers
C-bus protocol
0
0
S
0
0
1
0
0
Slave address
7
MSB
1
0
I
2
Table
C slave address byte
slave address
1
1
1
write bit
read bit
from PCF2127AT
from PCF2127AT
All information provided in this document is subject to legal disclaimers.
acknowledge
acknowledge
2
0
1
0
60.
C-bus slave address is 1010001. The entire I
6
0
(Table
A
A
0
Rev. 5 — 28 January 2013
0
0 to n data bytes
register address
65). In the write mode, a data transfer is terminated by sending
DATA BYTE
00h to 1Dh
1
write bit
from PCF2127AT
5
1
acknowledge
0
2
C-bus specification
A
from PCF2127AT
acknowledge
acknowledge
from master
4
0
register address
A
A
00h to 1Dh
STOP
Integrated RTC, TCXO and quartz crystal
P
LAST DATA BYTE
3
0
from PCF2127AT
acknowledge
Ref. 11 “UM10204”
A
no acknowledge
2
0
2
C-bus slave address byte
A
PCF2127AT
data bytes
0 to n
P
1
1
© NXP B.V. 2013. All rights reserved.
read register
data
and the
set register
address
from PCF2127AT
acknowledge
001aaj721
A
0
LSB
R/W
START/
STOP
001aaj719
P/S
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