ADSP-BF537 Blackfin Processor Hardware Reference
17-3
Watchdog Timer
External Interface
The watchdog timer does not directly interact with any pins of the chip.
Internal Interface
The watchdog timer is clocked by the system clock
SCLK
. Its registers are
accessed through the 16-bit peripheral access bus PAB. The 32-bit regis-
ters
WDOG_CNT
and
WDOG_STAT
must always be accessed by 32-bit read/write
operations. Hardware ensures that those accesses are atomic.
When the counter expires, one of three event requests can be generated.
Either a reset or an NMI request is issued to the Core Event Controller
(CEC) or a general-purpose interrupt request is passed to the System
Interrupt Controller (SIC).
Description of Operation
If enabled, the 32-bit watchdog timer counts downward every
SCLK
cycle.
If it becomes 0, one of three event requests can be issued to either the
CEC or the SIC. Depending on how the
WDEV
bit field in the
WDOG_CTL
register is programmed, the event that is generated may be a reset, a
non-maskable interrupt, or a general-purpose interrupt.
The counter value can be read through the 32-bit
WDOG_STAT
register. The
WDOG_STAT
register cannot, however, be written directly. Rather, software
writes the watchdog period value into the 32-bit
WDOG_CNT
register before
the watchdog is enabled. Once the watchdog is started, the period value
cannot be altered.
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 ...