Datasheet

PICPLC16 v6 Development System

MikroElektronika

page

13.0.

Input/Output Ports

Along the right side of the development system, there are four 10-pin connectors which are linked to the microcontroller’s I/O ports.

Microcontroller pins used for programming are not directly connected to the appropriate 10-pin connector CN2 (PORTB), but via a

multiplexer. DIP switches SW1-SW4 enable each connector pin to be connected to one pull-up/pull-down resistor. It depends on the

position of jumpers J5-J8 whether the port pins are to be connected to pull-up or pull-down resistors.

Figure 13-4: Port PORTB connection schematic

Figure 13-2: J6 in pull-down

position

Figure 13-3: J6 in pull-up

position

Jumper for pull-up/pull-

down resistor selection

Figure 13-1: I/O ports

DIP switch to enable pull-

up/pull-down resistor for

each port pin

PORTA/E 2x5 male connector

Additional module connected

to PORTB

Port PORTB pins are connected to pull-down resistors

Pull-up/pull-down resistors enable you to set the logic

level on all microcontroller’s input pins when they are

in idle state. This level depends on the position of the

pull-up/pull-down jumper J6. When this jumper is in

pull-up position, the input pins will be supplied with the

5V power supply voltage, which means that they will

be driven high (logic one (1)). When this jumper is in

pull-down position, the input pins will be supplied with

0V, i.e. they will be fed with a logic zero (0).

In order to provide some of the microcontroller pins

with a desired logic level, it is necessary to enable

connection between that pin and the resistor using the

appropriate DIP switch.

Refer to ﬁ gure 13-4. Port PORTB pins are driven low

(0). It means that jumper J6 is in pull-down position,

whereas switches on the DIP switch SW2 are in the

ON position.