C164CI datasheet(22/53 Pages) INFINEON

22 / 53 page

Semiconductor Group

1998-02

C164CI

A/D Converter

For analog signal measurement, a 10-bit A/D converter with 8 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 8 analog input channels, the remaining channel inputs can

be used as digital input port pins.

The A/D converter of the C164CI 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 (eg. 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.

C164CI Datasheet(PDF) 22 Page - Infineon Technologies AG