PCF2123BS NXP [NXP Semiconductors], PCF2123BS Datasheet - Page 15

• Manufacturer Part Number: PCF2123BS
• Description: SPI Real time clock/calendar
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
PCF2123_1
Product data sheet
Table 11.
[1]
[2]
Table 12.
[1]
[2]
Table 13.
[1]
[2]
Table 14.
[1]
Bit
7 and 6 -
12 hour mode
5
4 to 0
24 hour mode
5 to 0
Bit
7 and 6 -
5 to 0
Bit
7 to 3
2 to 0
Day
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Values shown in decimal.
Hour mode is set by the 12_24 bit in register Control_1.
Values shown in decimal.
The RTC compensates for leap years by adding a 29th day to February if the year counter contains a value
which is exactly divisible by 4, including the year 00.
These bits may be re-assigned by the user.
Values shown in decimal.
The weekday assignments may be re-defined by the user.
[1]
[1]
Symbol
AMPM
HOURS
HOURS
Symbol
DAYS
Symbol
-
WEEKDAYS
Register Hours (address 04h) bits description
Register Days (address 05h) bits description
Register Weekdays (address 06h) bits description
Weekday assignments
[2]
[2]
Upper-digit
Bit 7
X
X
X
X
X
X
X
Rev. 01 — 19 November 2008
Bit 6
X
X
X
X
X
X
X
Value
-
0
1
01 to 12
00 to 23
Value
-
01 to 31
Value
-
0 to 6
[2]
Bit 5
X
X
X
X
X
X
X
[1]
[1]
[1]
Description
unused
indicates AM
indicates PM
this register holds the current hours coded in BCD
format for 12 hour mode
this register holds the current hours coded in BCD
format for 24 hour mode
Description
unused
this register holds the current day coded in BCD
format
Description
unused
this register holds the current weekday, see
Bit 4
X
X
X
X
X
X
X
[2]
Digit
Bit 3
X
X
X
X
X
X
X
SPI Real time clock/calendar
Bit 2
0
0
0
0
1
1
1
PCF2123
© NXP B.V. 2008. All rights reserved.
Bit 1
0
0
1
1
0
0
1
Table 14
Bit 0
0
1
0
1
0
1
0
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