SAF-XC878CM-16FFI Infineon Technologies, SAF-XC878CM-16FFI Datasheet - Page 90

• Manufacturer Part Number: SAF-XC878CM-16FFI
• Description: MCU, 8BIT, 64K FLASH, 5V, 64LQFP
• Manufacturer: Infineon Technologies

Specifications of SAF-XC878CM-16FFI

• Controller Family/series: XC800
• Core Size: 8bit
• Program Memory Size: 64KB
• Ram Memory Size: 3328Byte
• No. Of Timers: 4
• No. Of Pwm Channels: 10
• Digital Ic Case Style: LQFP
• Supply Voltage Range: 4.5V To
• Peripherals: ADC, PWM, Timer
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

3.10
The Watchdog Timer (WDT) provides a highly reliable and secure way to detect and
recover from software or hardware failures. The WDT is reset at a regular interval that is
predefined by the user. The CPU must service the WDT within this interval to prevent the
WDT from causing an XC878 system reset. Hence, routine service of the WDT confirms
that the system is functioning properly. This ensures that an accidental malfunction of
the XC878 will be aborted in a user-specified time period.
In debug mode, the WDT is default suspended and stops counting. Therefore, there is
no need to refresh the WDT during debugging.
Features
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•
•
•
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The WDT is a 16-bit timer incremented by a count rate of
timer is realized as two concatenated 8-bit timers. The upper 8 bits of the WDT can be
preset to a user-programmable value via a watchdog service access in order to modify
the watchdog expire time period. The lower 8 bits are reset on each service access.
Figure 23
Figure 23
Data Sheet
ENWDT
ENWDT_P
16-bit Watchdog Timer
Programmable reload value for upper 8 bits of timer
Programmable window boundary
Selectable input frequency of
Time-out detection with NMI generation and reset prewarning activation (after which
a system reset will be performed)
f
PCLK
shows the block diagram of the WDT unit.
Watchdog Timer
Logic
WDT Block Diagram
1:128
1:2
f
PCLK
WDTIN
/2 or
MUX
81
f
PCLK
/128
WDT Low Byte
Control
WDT
Overflow/Time-out Control &
Window-boundary control
Clear
f
PCLK
/2 or
Functional Description
WDT High Byte
WDTWINB
WDTREL
f
PCLK
/128. This 16-bit
XC878CLM
V1.2, 2009-11
FNMIWDT
WDTRST
.