C167CR
A/D Converter
For analog signal measurement, a 10-bit A/D converter with 16 multiplexed input channels and a
sample and hold circuit has been integrated on-chip. It uses the method of successive
approximation. The sample time (for loading the capacitors) and the conversion time is
programmable and can so be adjusted to the external circuitry.
Overrun error detection/protection is provided for the conversion result register (ADDAT): either an
interrupt request will be generated when the result of a previous conversion has not been read from
the result register at the time the next conversion is complete, or the next conversion is suspended
in such a case until the previous result has been read.
For applications which require less than 16 analog input channels, the remaining channel inputs can
be used as digital input port pins.
The A/D converter of the C167CR supports four different conversion modes. In the standard Single
Channel conversion mode, the analog level on a specified channel is sampled once and converted
to a digital result. In the Single Channel Continuous mode, the analog level on a specified channel
is repeatedly sampled and converted without software intervention. In the Auto Scan mode, the
analog levels on a prespecified number of channels are sequentially sampled and converted. In the
Auto Scan Continuous mode, the number of prespecified channels is repeatedly sampled and
converted. In addition, the conversion of a specific channel can be inserted (injected) into a running
sequence without disturbing this sequence. This is called Channel Injection Mode.
The Peripheral Event Controller (PEC) may be used to automatically store the conversion results
into a table in memory for later evaluation, without requiring the overhead of entering and exiting
interrupt routines for each data transfer.
After each reset and also during normal operation the ADC automatically performs calibration
cycles. This automatic self-calibration constantly adjusts the converter to changing operating
conditions (e.g. temperature) and compensates process variations.
These calibration cycles are part of the conversion cycle, so they do not affect the normal operation
of the A/D converter.
Semiconductor Group
24
INFINEON [ Infineon ]
