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2 AT89C5132 Board
2.6
Internal/External Clock (Jumper X6)
The clock supply of the microcontroller can be determined by setting the
jumper X6. There are two possibilities for the controller's clock supply: The
controller can either get it's clock from the 20 MHz crystal oscillator on the
AT89C5132 board (Internal Clock) or from the CLKOUT2/4 pin of the VPC
3+ on the Extension board (External Clock):
Default
Figure 2-4: Settings of Jumper X6
2.7
Display Elements
The Extension Board has three LEDs: The green LED D10 indicates
correct power supply. The red LED D9 and the yellow LED D8 are
connected to the ports P1.4 and P1.5 of the controller.
2.8
I/O Area
The I/O area consist of 3 DIP switches (Port0, Port1, Port2) and 3 LED
lines.
The data bus lines to the DIP switches are connected via pulldown resistors
to GND. If a DIP switch is OFF, the corresponding input port of the
controller is connected via pulldown resistor to GND and the controller
therefore reads a logical '0' from this DIP-switch. If the DIP-switch is ON,
the controller's input is connected to VCC via the DIP-switch and the
controller therefore reads a logical '1' on this port.
2.9
Reset Button S4
The entire application can be reseted by pressing the Reset Button S4.The
microcontroller goes into a defined state and starts up the application
program.
6
External Clock
Internal Clock (Default)
Revision 2.00
VPC3+ Evaluation Kit
Copyright © profichip GmbH, 2005
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