Specifications
Table Of Contents
- Features
- Description
- Logic Block Diagram
- Contents
- Pin Configurations
- Pin Descriptions
- Absolute Maximum Ratings
- DC Characteristics (VCC = 2.7V-3.6V)
- AC Test Conditions
- Capacitance
- RTC DC Characteristics
- SRAM READ Cycles #1 and #2
- SRAM WRITE Cycles #1 and #2
- AutoStore/Power Up RECALL
- Software-Controlled STORE/RECALL Cycle
- Hardware STORE Cycle
- Soft Sequence Commands
- Mode Selection
- nvSRAM Operation
- Real Time Clock
- RTC Register Map
- Commercial and Industrial Ordering Information
- Ordering Codes
- Package Diagram
- Document History Page
- Sales, Solutions, and Legal Information
STK17T88
Document Number: 001-52040 Rev. *C Page 19 of 24
Register Map Detail
0x7FFF
Real Time Clock – Years
D7 D6 D5 D4 D3 D2 D1 D0
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 to 99.
0x7FFE
Real Time Clock – Months
D7 D6 D5 D4 D3 D2 D1 D0
0 0 0 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 to 12.
0x7FFD
Real Time Clock – Date
D7 D6 D5 D4 D3 D2 D1 D0
0 0 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 to 31.
Leap years are automatically adjusted for.
0x7FFC
Real Time Clock – Day
D7 D6 D5 D4 D3 D2 D1 D0
0 0 0 0 0 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
D7 D6 D5 D4 D3 D2 D1 D0
0 0 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 to 23.
0x7FFA
Real Time Clock – Minutes
D7 D6 D5 D4 D3 D2 D1 D0
0 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 to 59.
0x7FF9
Real Time Clock – Seconds
D7 D6 D5 D4 D3 D2 D1 D0
0 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 to 59.
0x7FF8
Calibration
D7 D6 D5 D4 D3 D2 D1 D0
OSCEN 0 Calibration
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.
Not Recommended for New Designs
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