ADSP-BF537 Blackfin Processor Hardware Reference
18-1
18 REAL-TIME CLOCK
This chapter describes the Real-Time Clock (RTC). Following an over-
view and list of key features is a description of operation. The chapter
concludes with a programming model, consolidated register definitions,
and programming examples.
Overview
The RTC provides a set of digital watch features to the processor, includ-
ing time of day, alarm, and stopwatch countdown. It is typically used to
implement either a real-time watch or a life counter, which counts the
elapsed time since the last system reset.
The RTC watch features are clocked by a 32.768 kHz crystal external to
the processor. The RTC uses dedicated power supply pins and is indepen-
dent of any reset, which enables it to maintain functionality even when
the rest of the 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
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 ...