STK17T88

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Register Map Detail (continued)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0x7FF0

 

 

 

 

 

 

Flags

 

 

 

 

 

 

 

D7

 

D6

D5

D4

 

D3

D2

D1

D0

 

 

 

 

 

 

 

 

 

WDF

 

AF

PF

OSCF

 

0

CAL

W

R

 

 

 

WDF

Watchdog

Timer Flag. This read-only bit is set to 1 when the watchdog timer is allowed to reach 0 without

 

 

 

 

being reset by the user. It is cleared to 0 when the Flags register is read or on power up

 

 

 

 

AF

Alarm Flag. This read-only bit is set to 1 when the time and date match the values stored in the alarm

 

 

 

registers with the match bits = 0. It is cleared when the Flags register is read or on power up

 

PF

Power-fail Flag. This read-only bit is set to 1 when power falls below the power-fail threshold VSWITCH. It

 

 

 

is cleared to 0 when the Flags register is read or on power up.

 

 

 

 

 

 

OSCF

Oscillator Fail Flag. Set to 1 on power up only if the oscillator is enabled and not running in the first 5ms

 

 

 

of operation. This indicates that the RTC backup power failed and the clock value is no longer valid. The

 

 

user must reset this bit to 0 to clear this condition.

 

 

 

 

 

 

 

CAL

Calibration Mode. When set to 1, a 512Hz square wave is output on the INT pin. When set to 0, the INT

 

 

 

pin resumes normal operation. This bit defaults to 0 (disabled) on power up.

 

 

 

 

WWrite Time. Setting the W bit to 1 freezes updates of the RTC registers. The user can then write to the RTC registers, Alarm registers, Calibration register, Interrupt register and Flags register. Setting the W bit to 0 disables writes to the registers and causes the contents of the real time clock registers to be transferred to the timekeeping counters if the time has changed (a new base time is loaded). The bit defaults to 0 on power up.

RRead Time. Setting the R bit to 1 captures the current time in holding registers so that clock updates are not during the reading process. Set the R bit to 0 to enable the holding register to resume clock updates. The bit defaults to 0 on power up.

Commercial and Industrial Ordering Information

STK17T88 - R F 45 I TR

Packaging Option:

TR = Tape and Reel

Blank = Tube

Temperature Range:

C - Commercial (0 to 70°C)

I - Industrial (-40 to 85°C)

Lead Finish

F = 100% Sn (Matte Tin) RoHS Compliant

Package:

R = Plastic 48-pin 330 mil SSOP

Ordering Codes

Speed:

25 - 25 ns

45 - 45 ns

Ordering Code

Description

Access Times (ns)

Temperature

STK17T88-RF25

3.3V 32Kx8 AutoStore nvSRAM+RTC SSOP48-300

25

Commercial

STK17T88-RF45

3.3V 32Kx8 AutoStore nvSRAM+RTC SSOP48-300

45

Commercial

STK17T88-RF25TR

3.3V 32Kx8 AutoStore nvSRAM+RTC SSOP48-300

25

Commercial

STK17T88-RF45TR

3.3V 32Kx8 AutoStore nvSRAM+RTC SSOP48-300

45

Commercial

STK17T88-RF25I

3.3V 32Kx8 AutoStore nvSRAM+RTC SSOP48-300

25

Industrial

STK17T88-RF45I

3.3V 32Kx8 AutoStore nvSRAM+RTC SSOP48-300

45

Industrial

STK17T88-RF25ITR

3.3V 32Kx8 AutoStore nvSRAM+RTC SSOP48-300

25

Industrial

STK17T88-RF45ITR

3.3V 32Kx8 AutoStore nvSRAM+RTC SSOP48-300

45

Industrial

Document Number: 001-52040 Rev. *A

 

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Cypress STK17T88 manual Ordering Codes, 0x7FF0 Flags, User must reset this bit to 0 to clear this condition