Phytec kitCON-161CS, Hardware Manual

Page: 37 / 62

Jumper

PHYTEC Meßtechnik GmbH 1999 L-356e_2
31
4.11 Reference Voltage of the A/D Converter J11, J12
The A/D converter of the controller requires a reference voltage
( V
AREF,
V
AGND
)
applied at pins 35 and 36 of the controller. This ref-
erence voltage can be derived either from an external source con-
nected to the kitCON-Connector pins 61/65 and 62/66 or from the
internal supply voltage of the kitCON-161CS/JC/JI. The source of the
reference voltage can be chosen with the jumpers J11 and J12.
Reference Voltage of the A/D
Converter J11 (
V
AGND
) J12 (
V
AREF
)
external reference voltage connected
to kitCON-Connector X3 pins 61/65
and 62/66 open open
derived from the internal supply
voltage of the kitCON-
161CS/JC/JI
closed* closed*
* = Default
-Setting
4.12 Configuration during System Reset DIP-Switch S3
Most of the programmable features of the C161x are either selected
during the initialization phase or repeatedly during program
execution. However there are some features that must be selected
earlier, because they are used for the first access of the program
execution. These selections are made during reset via the pins of Port
P0, which are read at the end of the internal reset sequence. During
reset, internal pull up devices are active at Port P0 meaning that high
input levels are the default configuration on Port P0. To change the
configuration external pull down devices have to be connected to the
respective port pins. This can be done with the help of DIP-Switch
S3, as DIP-Switch S3 allows the configuration of the board during
system reset (for more information about the configuration during
system reset refer also to the C161 User’s manual, section "System
Reset"). Some configurations that are usually made once can be
changed by installing optional resistors.