AN2848 Freescale Semiconductor / Motorola, AN2848 Datasheet - Page 2

• Manufacturer Part Number: AN2848
• Description: Programming the eTPU
• Manufacturer: Freescale Semiconductor / Motorola

Overview
1
The eTPU is an autonomous slave processor offered on various families of Freescale microcontrollers. It
is an enhanced version of the TPU, which has enjoyed one of the longest successes of any microcontroller
peripheral. Despite its popularity in specific markets, widespread adoption of the TPU was hindered by a
lack of high-level language support and limited availability of development tools.
The eTPU was designed from the start to be supported by a high-level language compiler, and as such has
become accessible to and adopted by a very wide range of customers even before the silicon had been
qualified. Many of these customers had previous TPU experience, and approaching the eTPU with an
understanding of the limitations of this type of device, found that they were pleasantly surprised at the
increased capabilities of the eTPU. However, the great expansion of resources inspired some of these
users to add features until they finally overwhelmed the capabilities of the device. Other users, never
having worked within the tight constraints of the TPU, discovered the limitations of the device trying to
implement overly ambitious designs approaches, and were obliged to scale back or even restart their
plans. This application note will offer some guidelines to help users streamline their design process
without running headlong into resource limits.
2
The eTPU is a slave co-processor tightly coupled to up to 32 I/O channels, each associated with an input
and an output signal; see
parameters in a data store which is simultaneously accessible to the host.
2
Byte Craft eTPU C Compiler User’s Manual
Overview
Architecture
Figure
1. The eTPU processing engine executes code from a code memory, using
Programming the eTPU, Rev. 0
Freescale Semiconductor