Stk17t88, Register map detail – Cypress AutoStore STK17T88 User Manual

Page 18

STK17T88

Document Number: 001-52040 Rev. *A

Page 18 of 22

Register Map Detail

0x7FFF

Real Time Clock – Years

10s Years

Years

Contains the lower two BCD digits of the year. Lower nibble contains the value for years; upper nibble
contains the value for 10s of years. Each nibble operates from 0 to 9. The range for the register is 0-99.

0x7FFE

Real Time Clock – Months

10s

Month

Months

Contains the BCD digits of the month. Lower nibble contains the lower digit and operates from 0 to 9; upper
nibble (one bit) contains the upper digit and operates from 0 to 1. The range for the register is 1-12.

0x7FFD

Real Time Clock – Date

10s Day of month

Day of month

Contains the BCD digits for the date of the month. Lower nibble contains the lower digit and operates from
0 to 9; upper nibble contains the upper digit and operates from 0 to 3. The range for the register is 1-31.
Leap years are automatically adjusted for.

0x7FFC

Real Time Clock – Day

Day of week

Lower nibble contains a value that correlates to day of the week. Day of the week is a ring counter that
counts from 1 to 7 then returns to 1. The user must assign meaning to the day value, as the day is not
integrated with the date.

0x7FFB

Real Time Clock – Hours

10s Hours

Hours

Contains the BCD value of hours in 24 hour format. Lower nibble contains the lower digit and operates
from 0 to 9; upper nibble (two bits) contains the upper digit and operates from 0 to 2. The range for the
register is 0-23.

0x7FFA

Real Time Clock – Minutes

10s Minutes

Minutes

Contains the BCD value of minutes. Lower nibble contains the lower digit and operates from 0 to 9; upper
nibble contains the upper minutes digit and operates from 0 to 5. The range for the register is 0-59.

0x7FF9

Real Time Clock – Seconds

10s Seconds

Seconds

Contains the BCD value of seconds. Lower nibble contains the lower digit and operates from 0 to 9; upper
nibble contains the upper digit and operates from 0 to 5. The range for the register is 0-59.

0x7FF8

Calibration

OSCEN

Calibratio

n Sign

Calibration

OSCEN

Oscillator Enable. When set to 1, the oscillator is disabled. When set to 0, the oscillator is enabled.
Disabling the oscillator saves battery/capacitor power during storage.

Calibration Sign

Determines if the calibration adjustment is applied as an addition to or as a subtraction from the time-base.

Calibration

These five bits control the calibration of the clock.

0x7FF7

Watchdog Timer

WDS

WDW

WDT

WDS

Watchdog Strobe. Setting this bit to 1 reloads and restarts the watchdog timer. The bit is cleared automat-
ically once the watchdog timer is reset. The WDS bit is write only. Reading it always will return a 0.

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