Conrad C-Control Pro Mega Series, Руководство пользователя

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19 C-Control Pro Mega Series
© 2008 Conrad Electronic
If x is a digital measuring value then the corresponding voltage value u is computed as follows:
u = x * Reference Voltage /
1024
Clock Generation
Clock generation takes place by a 14.7456MHz Quartz Oscillator. All time dependent actions within
the controller are derived from this clock frequency.
Reset
A Reset initiates the return of the Micro Controller system to a defined starting condition. In gerneral
the C-Control Pro Module knows two reset sources:
· Power-On-Reset: is automatically executed after switch on of the operating voltage.
· Hardware-Reset: is executed when the Module’s RESET (Pin 9) is pulled to "low" and released
again by e. g. shortly pressing the connected reset key RESET1 (SW3).
A "Brown-Out-Detection" avoids that the Controller can enter undefined conditions in case of
dropping operating voltages.
Digital Ports (PortA, PortB, PortC, PortD)
The C-Control Pro Module provides four digital ports at 8 pins each. To the digital ports it is possible
to connect e. g. pushbuttons with pull-up resistors, digital IC’s, opto couples or driver circuits for
relais. The ports can be addressed either separatly, i.e. pin by pin or byte by byte. Each pin can
either be input or output.
Never connect two ports directly together which should simultaneously work as outputs!
Digital input pins are high-impedance or wired to internal pull-up resistors and transform an applied
voltage signal into a logical value. For this it is required that the voltage signal is within the limits
defined for TTL and CMOS IC’s high or low levels. During further processing in the program the
logical values on the respective input ports are represented as 0 ("low") or 1 ("high"). Pins will take
on the values 0 or 1, Bytes from 0 to 255. Output ports are able to give out digital voltage signals by
use of an internal driver circuit. Connected circuits can draw (at high level) or feed (at low level) a
specific current from or to the ports.
Pay attention to the maximum admissable load current for a single port or for all ports in total.
Exceeding the maximal values may lead to destruction of the C-Control Pro Module. After a reset
each port is initially configured as input port. By certain commands the direction of data transport
can be toggled.
It is important to closely study the pin assignment of M32 and M128 prior to programming since
important functions of the program design (e. g. the USB interface of the application board) will apply
to specific ports. If these ports are re-programmed or if the matching jumpers on the application
board are no longer set then it may happen that the design platform can no longer transfer any
programs to the C-Control Pro. Timer inputs and outputs, A/D converter, I2C as well as serial
interface are also connected to various port pins.