Features

PXS20 Product Brief, Rev. 1

Freescale Semiconductor

25

2.5.36

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:

[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

2.5.37

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:

•

Duplicated module to guarantee highest possible diagnostic coverage (check of checker)

•

Multiple times replicated IPs are used as checkers on the SoR outputs

2.5.38

Voltage Regulator / Power Management Unit (PMU)

The on-chip voltage regulator module provides the following features:

•

Single external rail required

•

Single high supply required: nominal 3.3 V for packaged option

— Packaged option requires external ballast transistor due to reduced dissipation capacity at high

temperature but can use embedded transistor if power dissipation is maintained within package

dissipation capacity (lower frequency of operation)

•

All I/Os are at same voltage as external supply (3.3 V nominal)

•

Duplicated Low-Voltage Detectors (LVD) to guarantee proper operation at all stages (reset,

configuration, normal operation) and, to maximize safety coverage, one LVD can be tested while

the other operates (on-line self-testing feature)