ADSP-BF535 Blackfin Processor Hardware Reference
17-1
17 REAL-TIME CLOCK (RTC)
The Real-Time Clock (RTC) provides a set of digital watch features to the
ADSP-BF535 processor, including time of day, alarm, and stopwatch
countdown.
The RTC is clocked by a 32.768 kHz crystal external to the ADSP-BF535
processor. The RTC uses dedicated power supply pins, which enable it to
maintain functionality even when the rest of the ADSP-BF535 processor
is powered down.
The RTC input clock is divided down to a 1 Hz signal by a prescaler,
which can be bypassed. When bypassed, the RTC is clocked at the
32.768 kHz crystal rate. In normal operation, the prescaler is enabled.
The primary function of the RTC is to maintain an accurate day count
and time of day. The RTC accomplishes this by means of four counters:
• 60-second counter
• 60-minute counter
• 24-hour counter
• 255-day counter
The RTC increments the 60-second counter once per second and incre-
ments the other three counters when appropriate. The 255-day counter is
incremented each day at midnight (0 hours, 0 minutes, 0 seconds). The
RTC can generate an interrupt once per second, once per minute, and
once per day.
Содержание ADSP-BF535 Blackfin
Страница 80: ...Development Tools 1 26 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 312: ...Working With Memory 6 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 332: ...System Interfaces 7 20 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 360: ...Dynamic Power Management Controller 8 28 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 446: ...Beginning and Ending an SPI Transfer 10 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 522: ...Timing Examples 11 76 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 562: ...IrDA Support 12 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 608: ...PCI I O Issues 13 46 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 672: ...References 14 64 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 810: ...SDRAM Controller SDC 18 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 811: ...ADSP BF535 Blackfin Processor Hardware Reference 18 87 External Bus Interface Unit...
Страница 812: ...SDRAM Controller SDC 18 88 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 860: ...DMA Bus Debug Registers 20 30 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 908: ...SDRAM Controller External Bus Interface Unit B 36 ADSP BF535 Blackfin Processor Hardware Reference...