STK17T88

Register Map Detail (continued)

WDW

Watchdog Write Enable. Set this bit to 1 to disable writing of the watchdog time-out value (WDT5-WDT0).

 

This allows the user to strobe the watchdog without disturbing the time-out value. Setting this bit to 0 allows

 

bits 5-0 to be written.

 

 

 

 

 

 

 

 

 

WDT

Watchdog time-out selection. The watchdog timer interval is selected by the 6-bit value in this register. It

 

represents a multiplier of the 32 Hz count (31.25 ms). The range or time-out values is 31.25 ms (a setting

 

of 1) to 2 seconds (setting of 3Fh). Setting the watchdog timer register to 0 disables the timer. These bits

 

can be written only if the WDW bit was cleared to 0 on a previous cycle.

 

 

 

 

0x7FF6

 

 

 

 

 

Interrupt

 

 

 

 

 

D7

D6

 

D5

D4

 

D3

D2

 

D1

 

D0

 

 

 

 

 

 

WIE

AIE

 

PFIE

ABE

 

H/L

P/L

 

0

 

0

WIE

Watchdog

Interrupt Enable. When set to 1 and a watchdog time-out occurs, the watchdog timer drives the

 

INT pin and sets the WDF flag. When set to 0, the watchdog time-out only sets the WDF flag.

 

AIE

Alarm Interrupt Enable. When set to 1, the alarm match drives the INT pin and sets the AF flag. When set

 

to 0, the alarm match only sets the AF flag.

 

 

 

 

 

 

 

PFIE

Power-Fail Enable. When set to 1, a power failure drives the INT pin and sets the PF flag. When set to 0,

 

a power failure only sets the PF flag.

 

 

 

 

 

 

 

 

0

Reserved for Future Use

 

 

 

 

 

 

 

 

 

H/L

High/Low. When set to a 1, the INT pin is driven active high. When set to 0, the INT pin is open drain,

 

active low.

 

 

 

 

 

 

 

 

 

 

 

P/L

Pulse/Level. When set to a 1, the INT pin is driven active (determined by H/L) by an interrupt source for

 

approximately 200 ms. When set to a 0, the INT pin is driven to an active level (as set by H/L) until the

 

Flags register is read.

 

 

 

 

 

 

 

 

 

0x7FF5

 

 

 

 

Alarm – Day

 

 

 

 

 

D7

D6

D5

D4

 

D3

D2

 

D1

 

D0

 

 

 

 

 

M

0

 

10s Alarm Date

 

 

 

Alarm Date

 

Contains the alarm value for the date of the month and the mask bit to select or deselect the date value.

MMatch. Setting this bit to 0 causes the date value to be used in the alarm match. Setting this bit to 1 causes the match circuit to ignore the date value.

0x7FF4

 

 

 

Alarm – Hours

 

 

 

D7

D6

D5

D4

D3

D2

D1

D0

 

 

M

0

10s Alarm Hours

 

 

Alarm Hours

 

Contains the alarm value for the hours and the mask bit to select or deselect the hours value.

MMatch. Setting this bit to 0 causes the hours value to be used in the alarm match. Setting this bit to 1 causes the match circuit to ignore the hours value.

0x7FF3

 

 

 

Alarm – Minutes

 

 

 

D7

D6

D5

D4

D3

D2

D1

D0

 

 

M

 

10s Alarm Minutes

 

 

Alarm Minutes

 

Contains the alarm value for the minutes and the mask bit to select or deselect the minutes value.

MMatch. Setting this bit to 0 causes the minutes value to be used in the alarm match. Setting this bit to 1 causes the match circuit to ignore the minutes value.

0x7FF2

 

 

 

Alarm – Seconds

 

 

 

D7

D6

D5

D4

D3

D2

D1

D0

 

 

M

 

10s Alarm Seconds

 

 

Alarm Seconds

 

Contains the alarm value for the seconds and the mask bit to select or deselect the seconds’ value.

MMatch. Setting this bit to 0 causes the seconds’ value to be used in the alarm match. Setting this bit to 1 causes the match circuit to ignore the seconds value.

0x7FF1

Real Time Clock – Centuries

 

 

10s Centuries

 

Centuries

 

Contains the BCD value of Centuries. Lower nibble contains the

lower digit and operates from 0 to 9; upper

 

nibble contains the upper centuries digit and operates from 0 to 9. The range for the register is 0-99

 

centuries.

 

Document Number: 001-52040 Rev. *A

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Cypress STK17T88 0x7FF6 Interrupt, 0x7FF5 Alarm Day, 0x7FF4 Alarm Hours 10s Alarm Hours, 0x7FF3 Alarm Minutes, Centuries