ADSP-BF535 Blackfin Processor Hardware Reference
16-25
Timers
Watchdog Timer
The ADSP-BF535 processor includes a 32-bit timer that can be used to
implement a software watchdog function. A software watchdog can
improve system reliability by generating an event to the Blackfin core if
the timer expires before being updated by software. Depending on how
the watchdog timer is programmed, the event that is generated may be a
reset, a non-maskable interrupt, or a general-purpose interrupt. The
watchdog timer is clocked by the system clock (
SCLK
).
Watchdog Timer Operation
To use the watchdog timer:
1. Set the count value for the watchdog timer by writing the count
value into the Watchdog Count register (
WDOG_CNT
).
2. Copy the count value from
WDOG_CNT
into the Watchdog Status
register (
WDOG_STAT
) by executing a write to
WDOG_STAT
. For more
information, see
“Watchdog Status Register (WDOG_STAT)” on
page 16-26
.
3. In the Watchdog Control register (
WDOG_CTL
), select the event to be
generated upon timeout.
4. Enable the watchdog timer in
WDOG_CTL
.
5. The watchdog timer then begins counting down, decrementing the
value in the
WDOG_STAT
register. When the
WDOG_STAT
reaches 0, the
programmed event is generated. To prevent the event from being
generated, software must reload the count value from
WDOG_CNT
to
WDOG_STAT
by executing a write (of any value) to
WDOG_STAT
, or
must disable the watchdog timer in
WDOG_CTL
before the watchdog
timer expires.
Summary of Contents for ADSP-BF535 Blackfin
Page 80: ...Development Tools 1 26 ADSP BF535 Blackfin Processor Hardware Reference...
Page 312: ...Working With Memory 6 86 ADSP BF535 Blackfin Processor Hardware Reference...
Page 332: ...System Interfaces 7 20 ADSP BF535 Blackfin Processor Hardware Reference...
Page 360: ...Dynamic Power Management Controller 8 28 ADSP BF535 Blackfin Processor Hardware Reference...
Page 446: ...Beginning and Ending an SPI Transfer 10 40 ADSP BF535 Blackfin Processor Hardware Reference...
Page 522: ...Timing Examples 11 76 ADSP BF535 Blackfin Processor Hardware Reference...
Page 562: ...IrDA Support 12 40 ADSP BF535 Blackfin Processor Hardware Reference...
Page 608: ...PCI I O Issues 13 46 ADSP BF535 Blackfin Processor Hardware Reference...
Page 672: ...References 14 64 ADSP BF535 Blackfin Processor Hardware Reference...
Page 810: ...SDRAM Controller SDC 18 86 ADSP BF535 Blackfin Processor Hardware Reference...
Page 811: ...ADSP BF535 Blackfin Processor Hardware Reference 18 87 External Bus Interface Unit...
Page 812: ...SDRAM Controller SDC 18 88 ADSP BF535 Blackfin Processor Hardware Reference...
Page 860: ...DMA Bus Debug Registers 20 30 ADSP BF535 Blackfin Processor Hardware Reference...