Digilent 6021-210-000P-KIT - Manual (Page 9)

Universal Development Board™ Reference Manual
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Page 9 of 27
The determination of which PIC devices are compatible with the UDB board, and which socket to use is based on
the operating voltage range of the microcontroller and the layout of the power, ground and MCLR pins on the
device. The UDB operates the microcontroller at 3.3V and therefore, only devices that operate at 3.3V may be
used. Microchip® has several conventions for the placement of the power, ground and MCLR pins on their
microcontrollers. The following describes the way that the sockets are configured:
The socket at IC2 is designed to accommodate PIC12/PIC16 devices of up to 20 pins. On this socket, VDD is on pin
1, VSS is on pin 20, and MCLR is on pin 4. Any PIC device that matches this pin assignment will be usable. Note that
for smaller pin count devices, VSS will be on the highest numbered pin, e.g. pin 8 on an 8-pin device. The following
are some of the devices usable in this socket: PIC12F609, PIC12F615, PIC12F617, PIC12F1822, PIC12F1823,
PIC16F631, PIC16F677, PIC16F685, PIC16F687, PIC16F689, PIC16F690.
The socket at IC4 is designed to accommodate 28-pin PIC16/PIC18 devices. This socket is wired with MCLR on pin
1, VSS on pins 8 and 19, and VDD on pin 20. The following are some of the devices usable in this socket: PIC16F882,
PIC16F883, PIC16F886, PIC16F1933, PIC16F1936, PIC16F1938, PIC18F24J10, PIC18F25J10, PIC18F23K20,
PIC18F24K20, PIC18F25K20, PIC18F26K20.
The PIC24J10 and PIC25J10 microcontroller families have an internal voltage regulator for the core operating
voltage that requires an external bypass capacitor. For these devices, a 10uF capacitor must be connected to pin-6
on the microcontroller. The UDB board provides this capacitor and jumper JP6 is used to place it in or out of circuit.
When using a microcontroller in this family (or possibly others that have this same requirement), install a shorting
block onto JP6. These microcontrollers will operate erratically or not at all if this jumper is not installed. When
using other microcontroller families, the shorting block on JP6 should be removed. If this shorting block is not
removed, the 10uF capacitor will load down the I/O pin significantly slowing down its operation, and possibly
stressing the output driver due to excessive current flow when the pin is switching.
The socket at IC3 is designed to accommodate PIC24, dsPIC33 and PIC32 devices in 28-pin DIP packages. The
following are examples of PIC devices usable in this socket: PIC24FJxxxGA002 family, PIC24FJxxxGA102 family,
PIC24FJxxxGB004 family, dsPIC33FJxxxMC202 family, dsPIC33FJxxxMC302 family, dsPIC33FJxxxMC802 family,
dsPIC33FJxxxGP202 family, dsPIC33FJxxxGP302 family, dsPICFJxxxGP802 family, dsPIC33FJ06GS102,
dsPICFJ06GS202, dsPICFJ16GS402, dsPICFJ16GS502, any PIC32MX1xx or PIC32MX2xx device.
5.1 DIP Bus Program Signal Jumpers
Various jumpers must be set appropriately to configure the device programming signals depending on which DIP
socket is being used. Refer to section 6.3 below for information describing the jumper settings required.
5.2 DIP Bus Clock Jumper
The various PIC microcontrollers that can be used in the DIP sockets all have multiple options for the clock source
for the main processor clock. In many cases, an internal oscillator can be used and it is not necessary to set any
jumpers when using the internal oscillator. The UDB board provides an external oscillator that can be selected as a
clock source when an external oscillator is desired. No explicit provision is made for use of an external crystal or
resonator to make use of that clock option.
The UDB board provides an 8-pin DIP socket for an external oscillator. Refer to section 9 below for more
information about this oscillator.
Jumper JP7 is used to select the external clock source for the DIP socket being used. JP7 is located near the
20/14/8-pin DIP socket IC2 and the DIP bus header. Place the shorting block in the IC2 position to use the external