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BIT NAME Function
7 FLAPOPEN If set, flap open else flap closed
6 A19 If set, high level on A19 occurred during coma
5 FLAP If set, positive edge has occurred on FLAPOPEN
4 UART If set, an enabled UART interrupt is active
3 BTL If set, battery low pin is active
2 KEY If set, a column has gone low in snooze (or coma)
1 - -
0 TIME If set, an enabled TIME interrupt is active
UART is the result of TDRE, RDRF, DCDI and CTSI interrupt masked with UMK.
TIME is the result of TICK, SEC and MIN interrupt masked with TMK.
The logic is explained below :
UART = (UIT.TDRE & UMK.TDRE) | (UIT.RDRF & UMK.RDRF) | (UIT.DCDI & UMK.DCD) | (UIT.CTSI & UMK.CTS)
TIME = (TSTA.TICK & TMK.TICK) | (TSTA.SEC & TMK.SEC) | (TSTA.MIN & TMK.MIN)
The following diagram shows the how the registers combined defines the /INT signal (simplified):
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