SDA55XX Datasheet, PDF (147/230 Pages) Infineon Technologies AG – Preliminary & Confidential

SDA 55xx
Preliminary & Confidential
Analog Digital Converter (CADC)
16
Analog Digital Converter (CADC)
TVTpro includes a four channel 8-bit ADC for control purposes. By means of these four
input signals the controller is able to supervise the status of up to four analog signals and
take actions if necessary.
This analog signals can be connected to the port4 inputs without a special configuration.
If the port pins of port 4 are used as digital input, make sure that the input high level never
exceeds VDDA.
The input range of the ADC is fixed to the analog supply voltage range (2.5V nominal).
The conversion is done continuously on all four channels the results are stored in the
SFRs CADC0...CADC3 and updated automatically every 46µs. A interrupt can be used
to inform the processor about new available results.
16.1
Power Down and Wake Up
During idle mode it is required to reduce the power consummation dramatically. In order
to do this for the controller ADC a special wake up unit has been included. During this
mode only the signal on input channel 0 is observed. As soon as the input signal has
fallen below a predefined level an interrupt is triggered and the system wakes up.Two
different levels are available. The first one corresponds to (fullscale-4 LSB) the second
one to (fullscale-16 LSB). The actual level can be selected by a control bit (ADWULE).
Nevertheless it is possible to send even this wake up unit into power down (for detailed
description refer to power down chapter).
16.2
Register Description
Default after reset: 00_H
(MSB)
&$'&
SFR-Address D1
(LSB)
CADC0(7) CADC0(6) CADC0(5) CADC0(4) CADC0(3) CADC0(2) CADC0(1) CADC0(0)
CADC0(7..0):
ADC result of channel 1
After finishing the A to D conversion the processor is informed by
means of an interrupt. The interrupt service routine can now take
the conversion result of channel 1 from CADC0. The result will be
available for about 46µs after the interrupt.
Semiconductor Group
147
User’s Manual July 99