PCF2127 RTC example code with use of FRDM-KL25Z and OM13513 boards

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* The PCF2127T is a CMOS Real Time Clock (RTC) and calendar with an integrated
* Temperature Compensated Crystal Oscillator and a 32.768 kHz quartz crystal
* optimized for very high accuracy and very low power consumption.

* This simple example code has been written for the FRDM-KL25Z + OM13513
* boards in MCUXpresso IDE v10.1.0 and demonstrates how to set and read

* the time/date on the PCF2127T using the SPI (do not forget to remove the

* JP1 jumper) interface. It also illustrates how to use a minute interrupt to

* generate an interrupt on the INT pin once per minute when the Minutes

* register increments.
*
* In this example the date/time to be set is Wednesday, January 17 2018, 2:45 PM.
*
* Connection:     FRDM-KL25Z        OM13513
* VDD               J9-4                         P2-2
* GND               J9-18                       P2-1
* MOSI              J2-8                         P2-5
* MISO              J2-10                       P2-6
* SCLK             J2-12                       P2-4
* CS                  J2-6                        P2-3
* INT                 J1-6                        P2-8

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