PXS20 Datasheet, PDF (20/119 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller

Introduction
1.5.34 Junction Temperature Sensor
The junction temperature sensor provides a value via an ADC channel that can be used by software to calculate the device
junction temperature.
The key parameters of the junction temperature sensor include:
• Nominal temperature range from –40 to 150 °C
• Software temperature alarm via analog ADC comparator possible
1.5.35 Cross Triggering Unit (CTU)
The ADC cross triggering unit allows automatic generation of ADC conversion requests on user selected conditions without
CPU load during the PWM period and with minimized CPU load for dynamic configuration.
The CTU implements the following features:
• Cross triggering between ADC, PWM, eTimer, and external pins
• Double buffered trigger generation unit with as many as 8 independent triggers generated from external triggers
• Maximum operating frequency less than or equal to 120 MHz
• Trigger generation unit configurable in sequential mode or in triggered mode
• Trigger delay unit to compensate the delay of external low pass filter
• Double buffered global trigger unit allowing eTimer synchronization and/or ADC command generation
• Double buffered ADC command list pointers to minimize ADC-trigger unit update
• Double buffered ADC conversion command list with as many as 24 ADC commands
• Each trigger capable of generating consecutive commands
• ADC conversion command allows control of ADC channel from each ADC, single or synchronous sampling,
independent result queue selection
• DMA support with safety features
1.5.36 Cyclic Redundancy Checker (CRC) Unit
The CRC module is a configurable multiple data flow unit to compute CRC signatures on data written to its input register.
The CRC unit has the following features:
• 3 sets of registers to allow 3 concurrent contexts with possibly different CRC computations, each with a selectable
polynomial and seed
• Computes 16- or 32-bit wide CRC on the fly (single-cycle computation) and stores result in internal register.
The following standard CRC polynomials are implemented:
— x¹⁶ + x¹² + x⁵ + 1 [16-bit CRC-CCITT]
— x³² + x²⁶ + x²³ + x²² + x¹⁶ + x¹² + x¹¹ + x¹⁰ + x⁸ + x⁷ + x⁵ + x⁴ + x² + x + 1
[32-bit CRC-ethernet(32)]
• Key engine to be coupled with communication periphery where CRC application is added to allow implementation of
safe communication protocol
• Offloads core from cycle-consuming CRC and helps checking configuration signature for safe start-up or periodic
procedures
• CRC unit connected as peripheral bus on internal peripheral bus
• DMA support
1.5.37 Redundancy Control and Checker Unit (RCCU)
The RCCU checks all outputs of the sphere of replication (addresses, data, control signals). It has the following features:
PXS20 Microcontroller Data Sheet, Rev. 1
20
Freescale Semiconductor
Preliminary—Subject to Change Without Notice