Datasheet

Clock operation M41T82, M41T83
46/64 DocID012578 Rev 16
3.14.1 Active mode operation on V
CC
On V
CC
, the operation of the output circuit is as shown in Table 14.
When OUT is 0 and FT is 0, the pin will be 0 regardless of whether any interrupts are
enabled.
When FT is a 1, the 512 Hz signal will be output if OUT is 0 or if no interrupts are enabled.
The interrupt sources control the pin when OUT is 1 and one or more of the interrupts are
enabled.
If OUT is 1, FT is 0 and no interrupts are enabled, then the pin will be 1.
Table 14. Priority for IRQ1/FT/OUT pin when operating on V
CC
OUT
(1)
FT
(2)
A1IE
(3)
+ OFIE
(4)
+ TIE
(5)
+ watchdog
(6)
running
Pin Comment
00 x 0
When OUT is 0 and FT is not enabled, OUT dominates
and none of the interrupt sources have any effect.
01 x
512 Hz
When FT = 1 and OUT = 1 and no interrupts are enabled,
the output will be the 512 Hz frequency test (FT) signal.
x1 0
1x 1
IRQ
When one or more interrupts are enabled, and OUT is a 1,
the pin stays high until one of the interrupts is asserted.
10 0 1
When OUT is 1, FT is 0 and no interrupts are enabled, the
pin is high.
1. OUT is bit 7 of register 08h (digital calibration).
2. FT is bit 6 of register 08h (digital calibration).
3. A1IE is bit 7 of register 0Ah (alarm 1, month).
4. OFIE is bit 7 of register 09h (watchdog).
5. TIE is bit 5 of register 11h (timer control).
6. The watchdog is controlled by register 09h (watchdog).