PXS20 Datasheet, PDF (14/119 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller

Introduction
• 4 general purpose interrupt timers
• 32-bit counter resolution
• Can be used for software tick or DMA trigger operation
1.5.19 System Timer Module (STM)
The STM implements the following features:
• Up-counter with 4 output compare registers
The STM is replicated for each processor.
1.5.20 Software Watchdog Timer (SWT)
This module implements the following features:
• Fault tolerant output
• Safe internal RC oscillator as reference clock
• Windowed watchdog
• Program flow control monitor with 16-bit pseudorandom key generation
• Allows a high level of safety (SIL3 monitor)
The SWT module is replicated for each processor.
1.5.21 Fault Collection and Control Unit (FCCU)
The FCCU module has the following features:
• Redundant collection of hardware checker results
• Redundant collection of error information and latch of faults from critical modules on the device
• Collection of self-test results
• Configurable and graded fault control
— Internal reactions (no internal reaction, IRQ, Functional Reset, Destructive Reset, or Safe mode entered)
— External reaction (failure is reported to the external/surrounding system via configurable output pins)
1.5.22 System Integration Unit Lite (SIUL)
The SIUL controls MCU reset configuration, pad configuration, external interrupt, general purpose I/O (GPIO), internal
peripheral multiplexing, and system reset operation. The reset configuration block contains the external pin boot configuration
logic. The pad configuration block controls the static electrical characteristics of I/O pins. The GPIO block provides uniform
and discrete input/output control of the I/O pins of the MCU.
The SIU provides the following features:
• Centralized pad control on a per-pin basis
— Pin function selection
— Configurable weak pull-up/down
— Configurable slew rate control (slow/medium/fast)
— Hysteresis on GPIO pins
— Configurable automatic safe mode pad control
• Input filtering for external interrupts
PXS20 Microcontroller Data Sheet, Rev. 1
14
Freescale Semiconductor
Preliminary—Subject to Change Without Notice