C167CR
C167SR
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.
In order to decouple analog inputs from digital noise and to avoid input trigger noise
those pins used for analog input can be disconnected from the digital IO or input stages
under software control. This can be selected for each pin separately via register P5DIDIS
(Port 5 Digital Input Disable).
Data Sheet
28
V3.2, 2001-07
INFINEON [ Infineon ]
