AN2848 Freescale Semiconductor / Motorola, AN2848 Datasheet - Page 4

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

Architecture
Figure 2. Channel Block Diagram
The hardware associated with each channel is controlled by a number of registers, which determine actions
associated with the input and output pins and eTPU service requests. These registers are accessed by a
special purpose eTPU engine that can be programmed in C. The engine has a program store for the engine
software and a data store for function parameters. The memory blocks, whose size varies with the MCU,
are designed to be shared by two eTPUs, as well as being accessible to the host. Software threads in the
engine can be started by channel actions, and very complex control systems can be implemented that, once
started, can operate independently of the host.
Host action is required to setup the functions in the eTPU engine and channels, and the host may be
incorporated to a greater or lesser extent in the closing of an eTPU control loop. The host controls the
eTPU by writing the function code into the control store, writing the operating parameters into data store,
and configuring the basic functionality of the individual channels.
Programming the eTPU, Rev. 0
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