Datasheet

ManualsBrandsNXP SEMICONDUCTORS ManualsIntegrated Circuits (ICs)Timer IC t- real time clock Clock/calendar SO 20

Product data sheet Rev. 6 — 11 July 2013 83 of 86

NXP Semiconductors

PCF2127AT

Integrated RTC, TCXO and quartz crystal

25. Tables

Table 1. Ordering information. . . . . . . . . . . . . . . . . . . . . .2

Table 2. Ordering options . . . . . . . . . . . . . . . . . . . . . . . . .2

Table 3. Marking codes . . . . . . . . . . . . . . . . . . . . . . . . . .2

Table 4. Pin description of SO20 (PCF2127AT) . . . . . . .4

Table 5. Register overview . . . . . . . . . . . . . . . . . . . . . . .8

Table 6. Control_1 - control and status register 1

(address 00h) bit description . . . . . . . . . . . . . .10

Table 7. Control_2 - control and status register 2

(address 01h) bit description . . . . . . . . . . . . . .11

Table 8. Control_3 - control and status register 3

(address 02h) bit description . . . . . . . . . . . . . .12

Table 9. CLKOUT_ctl - CLKOUT control register

(address 0Fh) bit description . . . . . . . . . . . . . .13

Table 10. Temperature measurement period . . . . . . . . . .13

Table 11. CLKOUT frequency selection. . . . . . . . . . . . . .14

Table 12. Aging_offset - crystal aging offset register

(address 19h) bit description . . . . . . . . . . . . . .15

Table 13. Frequency correction at 25 °C, typical . . . . . . .15

Table 14. RAM_addr_MSB - RAM address MSB register

(address 1Ah) bit description . . . . . . . . . . . . . .16

Table 15. RAM_addr_LSB - RAM address LSB register

(address 1Bh) bit description . . . . . . . . . . . . . .16

Table 16. RAM_wrt_cmd - RAM write command register

(address 1Ch) bit description . . . . . . . . . . . . . .16

Table 17. RAM_rd_cmd - RAM read command register

(address 1Dh) bit description . . . . . . . . . . . . . .16

Table 18. Power management control bit description . . .18

Table 19. Output pin BBS. . . . . . . . . . . . . . . . . . . . . . . . .22

Table 20. Seconds - seconds and clock integrity

Table 21. Seconds coded in BCD format . . . . . . . . . . . .30

Table 22. Minutes - minutes register (address 04h) bit

description . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

Table 23. Hours - hours register (address 05h) bit

description . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Table 24. Days - days register (address 06h) bit

description . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Table 25. Weekdays - weekdays register (address 07h)

bit description . . . . . . . . . . . . . . . . . . . . . . . . . .31

Table 26. Weekday assignments . . . . . . . . . . . . . . . . . . .31

Table 27. Months - months register (address 08h) bit

description . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

Table 28. Month assignments in BCD format. . . . . . . . . .32

Table 29. Years - years register (address 09h) bit

description . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

Table 30. Second_alarm - second alarm register

(address 0Ah) bit description . . . . . . . . . . . . . .34

Table 31. Minute_alarm - minute alarm register

(address 0Bh) bit description . . . . . . . . . . . . . .35

Table 32. Hour_alarm - hour alarm register

(address 0Ch) bit description . . . . . . . . . . . . . .35

Table 33. Day_alarm - day alarm register

(address 0Dh) bit description . . . . . . . . . . . . . .35

Table 34. Weekday_alarm - weekday alarm register

(address 0Eh) bit description . . . . . . . . . . . . . .36

Table 35. Watchdg_tim_ctl - watchdog timer control

Table 36. Watchdg_tim_val - watchdog timer value

Table 37. Programmable watchdog or countdown timer . 38

Table 38. Specification of t

w(rst)

. . . . . . . . . . . . . . . . . . . . 40

Table 39. First period delay for timer counter . . . . . . . . . 41

Table 40. Flag location in register Control_2 . . . . . . . . . . 41

Table 41. Example values in register Control_2 . . . . . . . 42

Table 42. Example to clear only CDTF (bit 3) . . . . . . . . . 42

Table 43. Example to clear only AF (bit 4). . . . . . . . . . . . 42

Table 44. Example to clear only MSF (bit 7) . . . . . . . . . . 42

Table 45. Example to clear both CDTF and MSF . . . . . . 42

Table 46. Timestp_ctl - timestamp control register

(address 12h) bit description . . . . . . . . . . . . . . 44

Table 47. Sec_timestp - second timestamp register

(address 13h) bit description . . . . . . . . . . . . . . 44

Table 48. Min_timestp - minute timestamp register

(address 14h) bit description . . . . . . . . . . . . . . 44

Table 49. Hour_timestp - hour timestamp register

(address 15h) bit description . . . . . . . . . . . . . . 45

Table 50. Day_timestp - day timestamp register

(address 16h) bit description . . . . . . . . . . . . . . 45

Table 51. Mon_timestp - month timestamp register

(address 17h) bit description . . . . . . . . . . . . . . 45

Table 52. Year_timestp - year timestamp register

(address 18h) bit description . . . . . . . . . . . . . . 45

Table 53. Battery switch-over and timestamp . . . . . . . . . 46

Table 54. Effect of bits MI and SI on pin INT

and bit

MSF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Table 55. INT

operation (bit TI_TP = 1) . . . . . . . . . . . . . . 50

Table 56. First increment of time circuits after stop

release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Table 57. Interface selection input pin IFS. . . . . . . . . . . . 56

Table 58. Serial interface. . . . . . . . . . . . . . . . . . . . . . . . . 57

Table 59. Command byte definition . . . . . . . . . . . . . . . . . 58

Table 60. I

C slave address byte. . . . . . . . . . . . . . . . . . . 61

Table 61. Limiting values . . . . . . . . . . . . . . . . . . . . . . . . . 65

Table 62. Static characteristics . . . . . . . . . . . . . . . . . . . . 66

Table 63. Frequency characteristics . . . . . . . . . . . . . . . . 70

Table 64. SPI-bus characteristics . . . . . . . . . . . . . . . . . . 71

Table 65. I

C-bus characteristics. . . . . . . . . . . . . . . . . . . 73

Table 66. Carrier tape dimensions of PCF2127AT . . . . . 76

Table 67. Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . 78

Table 68. Revision history . . . . . . . . . . . . . . . . . . . . . . . . 80