InetrfaceProducts NXP / PCF2127

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

PCF2127.h@0:1377bcf1455e, 2014-12-04 (annotated)

Committer:
nxp_ip
Date:
Thu Dec 04 04:58:24 2014 +0000
Revision:
0:1377bcf1455e
Child:
1:700e0285cfd8
initial version

Who changed what in which revision?

UserRevisionLine numberNew contents of line
nxp_ip 0:1377bcf1455e 1 /*
nxp_ip 0:1377bcf1455e 2 * PCF2127 library
nxp_ip 0:1377bcf1455e 3 *
nxp_ip 0:1377bcf1455e 4 * @author Akifumi (Tedd) OKANO, NXP Semiconductors
nxp_ip 0:1377bcf1455e 5 * @version 1.5
nxp_ip 0:1377bcf1455e 6 * @date 04-Dec-2014
nxp_ip 0:1377bcf1455e 7 *
nxp_ip 0:1377bcf1455e 8 * PCF2127 is a "real time clock (RTC)" module which is including a Xtal and TCXO
nxp_ip 0:1377bcf1455e 9 * http://www.nxp.com/products/interface_and_connectivity/real_time_clocks/rtcs_with_temp_compensation/series/PCF2127.html
nxp_ip 0:1377bcf1455e 10 *
nxp_ip 0:1377bcf1455e 11 * RTC initializing part is ported from..
nxp_ip 0:1377bcf1455e 12 * http://mbed.org/users/roen/notebook/real-time/
nxp_ip 0:1377bcf1455e 13 *
nxp_ip 0:1377bcf1455e 14 * This code is refined version of..
nxp_ip 0:1377bcf1455e 15 * http://developer.mbed.org/users/okano/code/NXP_PCF2127A/
nxp_ip 0:1377bcf1455e 16 */
nxp_ip 0:1377bcf1455e 17
nxp_ip 0:1377bcf1455e 18 #ifndef MBED_PCF2127
nxp_ip 0:1377bcf1455e 19 #define MBED_PCF2127
nxp_ip 0:1377bcf1455e 20
nxp_ip 0:1377bcf1455e 21 #include "mbed.h"
nxp_ip 0:1377bcf1455e 22
nxp_ip 0:1377bcf1455e 23 class PCF2127
nxp_ip 0:1377bcf1455e 24 {
nxp_ip 0:1377bcf1455e 25 public:
nxp_ip 0:1377bcf1455e 26
nxp_ip 0:1377bcf1455e 27 /** name of the PCF2127 registers */
nxp_ip 0:1377bcf1455e 28 typedef enum {
nxp_ip 0:1377bcf1455e 29 Control_1,
nxp_ip 0:1377bcf1455e 30 Control_2,
nxp_ip 0:1377bcf1455e 31 Control_3,
nxp_ip 0:1377bcf1455e 32 Seconds,
nxp_ip 0:1377bcf1455e 33 Minutes,
nxp_ip 0:1377bcf1455e 34 Hours,
nxp_ip 0:1377bcf1455e 35 Days,
nxp_ip 0:1377bcf1455e 36 Weekdays,
nxp_ip 0:1377bcf1455e 37 Months,
nxp_ip 0:1377bcf1455e 38 Years,
nxp_ip 0:1377bcf1455e 39 Second_alarm,
nxp_ip 0:1377bcf1455e 40 Minute_alarm,
nxp_ip 0:1377bcf1455e 41 Hour_alarm,
nxp_ip 0:1377bcf1455e 42 Day_alarm,
nxp_ip 0:1377bcf1455e 43 Weekday_alarm,
nxp_ip 0:1377bcf1455e 44 CLKOUT_ctl,
nxp_ip 0:1377bcf1455e 45 Watchdg_tim_ctl,
nxp_ip 0:1377bcf1455e 46 Watchdg_tim_val,
nxp_ip 0:1377bcf1455e 47 Timestp_ctl,
nxp_ip 0:1377bcf1455e 48 Sec_timestp,
nxp_ip 0:1377bcf1455e 49 Min_timestp,
nxp_ip 0:1377bcf1455e 50 Hour_timestp,
nxp_ip 0:1377bcf1455e 51 Day_timestp,
nxp_ip 0:1377bcf1455e 52 Mon_timestp,
nxp_ip 0:1377bcf1455e 53 Year_timestp,
nxp_ip 0:1377bcf1455e 54 Aging_offset
nxp_ip 0:1377bcf1455e 55 }
nxp_ip 0:1377bcf1455e 56 RegisterName;
nxp_ip 0:1377bcf1455e 57
nxp_ip 0:1377bcf1455e 58 /** Create a PCF2127 instance connected to specified I2C pins with specified address
nxp_ip 0:1377bcf1455e 59 *
nxp_ip 0:1377bcf1455e 60 * @param I2C_sda I2C-bus SDA pin
nxp_ip 0:1377bcf1455e 61 * @param I2C_scl I2C-bus SCL pin
nxp_ip 0:1377bcf1455e 62 * @param vControl_1 (option) data for Control_1 register
nxp_ip 0:1377bcf1455e 63 * @param vControl_2 (option) data for Control_2 register
nxp_ip 0:1377bcf1455e 64 * @param vControl_3 (option) data for Control_3 register
nxp_ip 0:1377bcf1455e 65 */
nxp_ip 0:1377bcf1455e 66 PCF2127( PinName sda, PinName sdl, char vControl_1 = 0x03, char vControl_2 = 0x00, char vControl_3 = 0x60 );
nxp_ip 0:1377bcf1455e 67
nxp_ip 0:1377bcf1455e 68 /** Destractor
nxp_ip 0:1377bcf1455e 69 */
nxp_ip 0:1377bcf1455e 70 ~PCF2127();
nxp_ip 0:1377bcf1455e 71
nxp_ip 0:1377bcf1455e 72 /** Clock integrity check
nxp_ip 0:1377bcf1455e 73 *
nxp_ip 0:1377bcf1455e 74 * @return non-zero value if the clock was stopped (means need to set the time)
nxp_ip 0:1377bcf1455e 75 */
nxp_ip 0:1377bcf1455e 76 int is_init_required( void );
nxp_ip 0:1377bcf1455e 77
nxp_ip 0:1377bcf1455e 78 /** Set the time
nxp_ip 0:1377bcf1455e 79 *
nxp_ip 0:1377bcf1455e 80 * @param dtp Pointer to struct tm
nxp_ip 0:1377bcf1455e 81 */
nxp_ip 0:1377bcf1455e 82 void set_time( struct tm *dtp );
nxp_ip 0:1377bcf1455e 83
nxp_ip 0:1377bcf1455e 84 /** Set the time
nxp_ip 0:1377bcf1455e 85 * @param s String data: The time information should be given in format of "YYYY MM DD HH MM SS"
nxp_ip 0:1377bcf1455e 86 */
nxp_ip 0:1377bcf1455e 87 void set_time( char *s );
nxp_ip 0:1377bcf1455e 88
nxp_ip 0:1377bcf1455e 89 /** Get time of day
nxp_ip 0:1377bcf1455e 90 *
nxp_ip 0:1377bcf1455e 91 * This function works similar to "time()" in standard-C-library
nxp_ip 0:1377bcf1455e 92 *
nxp_ip 0:1377bcf1455e 93 * @param tp Pointer to time_t
nxp_ip 0:1377bcf1455e 94 */
nxp_ip 0:1377bcf1455e 95 time_t time( time_t *tp );
nxp_ip 0:1377bcf1455e 96
nxp_ip 0:1377bcf1455e 97 /** Register access interface with integer to BCD conversion
nxp_ip 0:1377bcf1455e 98 *
nxp_ip 0:1377bcf1455e 99 * @param addr Register address
nxp_ip 0:1377bcf1455e 100 * @param Integer data. Converted to BCD before writing inot the register.
nxp_ip 0:1377bcf1455e 101 */
nxp_ip 0:1377bcf1455e 102 void set_alarm( char addr, char s );
nxp_ip 0:1377bcf1455e 103
nxp_ip 0:1377bcf1455e 104 /** Clear interrupt flag
nxp_ip 0:1377bcf1455e 105 *
nxp_ip 0:1377bcf1455e 106 * Clears interrupt flags by writing 0x00 into Control_2 register
nxp_ip 0:1377bcf1455e 107 *
nxp_ip 0:1377bcf1455e 108 */
nxp_ip 0:1377bcf1455e 109 void clear_intr( void );
nxp_ip 0:1377bcf1455e 110
nxp_ip 0:1377bcf1455e 111 private:
nxp_ip 0:1377bcf1455e 112 void set_register( char addr, char data );
nxp_ip 0:1377bcf1455e 113 char read_register( char addr );
nxp_ip 0:1377bcf1455e 114 char i2bcd( char n );
nxp_ip 0:1377bcf1455e 115 char bcd2i( char bcd );
nxp_ip 0:1377bcf1455e 116
nxp_ip 0:1377bcf1455e 117 I2C i2c;
nxp_ip 0:1377bcf1455e 118 char device_address;
nxp_ip 0:1377bcf1455e 119 }
nxp_ip 0:1377bcf1455e 120 ;
nxp_ip 0:1377bcf1455e 121 #endif // end of "#ifndef MBED_PCF2127"