PSB21473FV13XT Infineon Technologies, PSB21473FV13XT Datasheet - Page 180

• Manufacturer Part Number: PSB21473FV13XT
• Manufacturer: Infineon Technologies

Specifications of PSB21473FV13XT

• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (min): 3.135V
• Operating Supply Voltage (max): 3.6V
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 144
• Lead Free Status / RoHS Status: Compliant

INCA-D
PSB 21473
The Watchdog Timer (WDT)
12
The Watchdog Timer (WDT)
To allow recovery from software or hardware failure, the INCA-D provides a Watchdog
Timer. If the software fails to service this timer before an overflow occurs, an internal
reset sequence will be initiated. This internal reset will also pull the RSTOUT pin low,
which also resets the peripheral hardware, which might be the cause for the malfunction.
When the watchdog timer is enabled and the software has been designed to service it
regularly before it overflows, the watchdog timer will supervise the program execution,
as it only will overflow if the program does not progress properly. The watchdog timer will
also time out, if a software error was due to hardware related failures. This prevents the
controller from malfunctioning for longer than a user-specified time.
The watchdog timer provides two registers: a read-only timer register that contains the
current count, and a control register for initialization.
Reset Indication Pin
Data Registers
Control Registers
WDT
WDTCON
RSTOUT
Figure 12-1 SFRs and Port Pins associated with the Watchdog Timer
The watchdog timer is a 16-bit up counter which can be clocked with the CPU clock (f
)
CPU
either divided by 2 or divided by 128. This 16-bit timer is realized as two concatenated
8-bit timers (see figure below). The upper 8 bits of the watchdog timer can be preset to
a user-programmable value via a watchdog service access in order to vary the watchdog
expire time. The lower 8 bits are reset on each service access.
Figure 12-2 Watchdog Timer Block Diagram
Data Sheet
180
2003-03-31