Interface Overview
18-2
ADSP-BF537 Blackfin Processor Hardware Reference
• 24-hour counter
• 32768-day counter
The RTC increments the 60-second counter once per second and incre-
ments the other three counters when appropriate. The 32768-day counter
is incremented each day at midnight (0 hours, 0 minutes, 0 seconds).
Interrupts can be issued periodically, either every second, every minute,
every hour, or every day. Each of these interrupts can be independently
controlled.
The RTC provides two alarm features, programmed with the RTC Alarm
register (
RTC_ALARM
). The first is a time of day alarm (hour, minute, and
second). When the alarm interrupt is enabled, the RTC generates an inter-
rupt each day at the time specified. The second alarm feature allows the
application to specify a day as well as a time. When the day alarm inter-
rupt is enabled, the RTC generates an interrupt on the day and time
specified. The alarm interrupt and day alarm interrupt can be enabled or
disabled independently.
The RTC provides a stopwatch function that acts as a countdown timer.
The application can program a second count into the RTC stopwatch
count register (
RTC_SWCNT
). When the stopwatch interrupt is enabled and
the specified number of seconds have elapsed, the RTC generates an
interrupt.
Interface Overview
The RTC external interface consists of two clock pins, which together
with the external components form the reference clock circuit for the
RTC. The RTC interfaces internally to the processor system through the
Peripheral Access Bus (PAB), and through the interrupt interface to the
SIC (System Interrupt Controller).
Summary of Contents for Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...