
XC878CLM
Functional Description
Data Sheet
96
V1.1, 2009-08
3.20
Capture/Compare Unit 6
The Capture/Compare Unit 6 (CCU6) provides two independent timers (T12, T13), which
can be used for Pulse Width Modulation (PWM) generation, especially for AC-motor
control. The CCU6 also supports special control modes for block commutation and
multi-phase machines.
The timer T12 can function in capture and/or compare mode for its three channels. The
timer T13 can work in compare mode only.
The multi-channel control unit generates output patterns, which can be modulated by
T12 and/or T13. The modulation sources can be selected and combined for the signal
modulation.
Timer T12 Features
Three capture/compare channels, each channel can be used either as a capture or
as a compare channel
Supports generation of a three-phase PWM (six outputs, individual signals for
highside and lowside switches)
16-bit resolution, maximum count frequency = peripheral clock frequency
Dead-time control for each channel to avoid short-circuits in the power stage
Concurrent update of the required T12/13 registers
Generation of center-aligned and edge-aligned PWM
Supports single-shot mode
Supports many interrupt request sources
Hysteresis-like control mode
Timer T13 Features
One independent compare channel with one output
16-bit resolution, maximum count frequency = peripheral clock frequency
Can be synchronized to T12
Interrupt generation at period-match and compare-match
Supports single-shot mode
Additional Features
Implements block commutation for Brushless DC-drives
Position detection via Hall-sensor pattern
Automatic rotational speed measurement for block commutation
Integrated error handling
Fast emergency stop without CPU load via external signal (CTRAP)
Control modes for multi-channel AC-drives
Output levels can be selected and adapted to the power stage
The block diagram of the CCU6 module is shown in Figure 28.