PCF2127 and PCF2129 are high accuracy real-time-clock (RTC) module. This library provides simple interface to accessing clock information.

Dependents:   PCF2127_Demo PCF2127_Hello

PCF2127 and PCF2129

PCF2127T PCF2127T is in SO16 package

The PCF2127 and the PCF2129 are a CMOS Real Time Clock (RTC) and calendar with an integrated Temperature Compensated Crystal (Xtal) Oscillator (TCXO) and a 32.768 kHz quartz crystal optimized for very high accuracy and very low power consumption.
Both of PCF2127 and PCF2129 have a selectable I2C-bus or SPI-bus, a backup battery switch-over circuit, a programmable watchdog function, a timestamp function, and many other features.
On addition to this, the PCF2127 has 512 bytes of general-purpose static RAM.

These 4 types of RTC modules are software compatible. So this library "PCF2127" can be used all of those.
This library only supports I2C to communicate with the PCF2127/PCF2129.

Type variations

Main feature difference

type+/-3ppm accuracy range512 bytes RAMpackage
PCF2127T-30℃ to +80℃yesSO16
PCF2127AT-30℃ to +60℃yesSO20
PCF2129T-30℃ to +80℃not availableSO16
PCF2129AT-15℃ to +60℃not availableSO20

Pin assign

/media/uploads/nxp_ip/pcf2127_pcf2129_pin_assign.png

PCF2127T
PCF2127T

Connection between MCU and PCF2127/PCF2129

These examples show how the RTC module can be connected via I2C bus.

http://developer.mbed.org/media/components/pinouts/both_types_connection3.png

References

History

online document (class description) updated default tip

2014-12-10, by nxp_ip [Wed, 10 Dec 2014 02:07:35 +0000] rev 3

online document (class description) updated


internal RAM access API has been added (for PCF2127 only)

2014-12-10, by nxp_ip [Wed, 10 Dec 2014 01:43:30 +0000] rev 2

internal RAM access API has been added (for PCF2127 only)


version 1.6:; changed: "battery switch-over function" as standard mode; changed: "CLKOUT" frequency is 1Hz; added: constructor by I2C object; added: set_time( time_t *tp ) function

2014-12-09, by nxp_ip [Tue, 09 Dec 2014 07:21:13 +0000] rev 1

version 1.6:; changed: "battery switch-over function" as standard mode; changed: "CLKOUT" frequency is 1Hz; added: constructor by I2C object; added: set_time( time_t *tp ) function


initial version

2014-12-04, by nxp_ip [Thu, 04 Dec 2014 04:58:24 +0000] rev 0

initial version