140703
Real-Time Clock/Calendar
A real-time clock is used as the AT-compatible clock/calendar. It supports a number of features including periodic and
alarm interrupt capabilities. In addition to the time and date keeping functions, the system configuration is kept in CMOS
RAM contained within the clock section. A battery must be enabled for the real-time clock to retain time and date during a
power down.
A status LED is populated on the board at
D6
, which can be used for any application purpose. The LED is turned on
during the boot process and can be turned off by writing a
0
to hex address 0x29D bit 0. The status LED can then be
toggled on by writing a
1
and off by writing a
0
to the same address.
STATUS LED
D6
--
GREEN
STATUS
D6 - Status LED
