Microchip Technology DM163024 User Manual
Reconfiguring and Restoring the PICDEM.net 2 Development Board
2011 Microchip Technology Inc.
DS51623D-page 23
3.2.1.1
USER-DEFINED CONTROLS AND THE LED BANK
The potentiometer and the user-defined push buttons are each connected to the
PIC18F97J60 through their own individual jumpers. They may be selectively disabled
to allow individual ports to become available for general I/O purposes.
PIC18F97J60 through their own individual jumpers. They may be selectively disabled
to allow individual ports to become available for general I/O purposes.
The LED bank (D1 through D8) is enabled as a group with one jumper (JP4).
3.2.1.2
TIMER1 OSCILLATOR (Y3)
By default, ports, RC0 and RC1, are configured for use by the Timer1 oscillator. An
appropriate oscillator circuit, including Y3, C45 and C46, is connected across these
pins. Removing jumpers, JP17 and/or JP22, disconnects the circuit and makes one or
both pins available as I/O ports.
appropriate oscillator circuit, including Y3, C45 and C46, is connected across these
pins. Removing jumpers, JP17 and/or JP22, disconnects the circuit and makes one or
both pins available as I/O ports.
3.2.1.3
ETHERNET LEDs
As shipped, the PICDEM.net 2 Development Board uses pins, RA0 and RA1, of the
microcontroller to drive the Ethernet LEDs in J1, generically known as LEDA (the
Activity LED) and LEDB (the Link LED). These signals are also present on RA0 and
RA1 of the PICtail Daughter Board header. Jumpers, JP6, JP7, JP8 and JP10, are used
to connect or disconnect the microcontroller from either the LEDs or the header, or from
both. This is useful in situations when RA0 and RA1 are being used as general I/O pins
and are not needed for network indication.
microcontroller to drive the Ethernet LEDs in J1, generically known as LEDA (the
Activity LED) and LEDB (the Link LED). These signals are also present on RA0 and
RA1 of the PICtail Daughter Board header. Jumpers, JP6, JP7, JP8 and JP10, are used
to connect or disconnect the microcontroller from either the LEDs or the header, or from
both. This is useful in situations when RA0 and RA1 are being used as general I/O pins
and are not needed for network indication.
3.2.1.4
ENC28J60 OPERATION
The Reset state of the ENC28J60 controller is determined by jumper, JP5. There are
three possible configurations:
three possible configurations:
• RD4 (1-2 bridged): The RESET pin is tied to RD4 of the PIC18F97J60. This
allows the microcontroller to execute hardware Resets of the ENC28J60 and use
it as an external Ethernet transceiver.
it as an external Ethernet transceiver.
• Disabled (2-3 bridged): The RESET pin is tied to ground, holding the ENC28J60
in permanent Reset and effectively disabling it.
• Open (no jumper): The RESET pin is disconnected, preventing hardware Resets
but still allowing software device Resets from the SPI bus. This setting also allows
the PIC18F97J60 to use the ENC28J60 as an Ethernet transceiver.
the PIC18F97J60 to use the ENC28J60 as an Ethernet transceiver.
By default, JP5 is configured as “Open” (no jumper).
3.2.2
Using the ENC28J60 as the Ethernet Interface
As shipped, the Development Board uses the Ethernet interface module on the
PIC18F97J60 controller for network connectivity. In this state, J1 is the only active
Ethernet port; J2 is not functional.
PIC18F97J60 controller for network connectivity. In this state, J1 is the only active
Ethernet port; J2 is not functional.
It is possible to configure the board to bypass the microcontroller’s on-chip Ethernet
module and use the ENC28J60 interface for connectivity. All of the necessary circuit
connections on the board have already been made. The main factor preventing the
ENC28J60 from being used is that the preprogrammed Microchip TCP/IP Demo
Application has been designed to use the microcontroller’s on-chip Ethernet module.
module and use the ENC28J60 interface for connectivity. All of the necessary circuit
connections on the board have already been made. The main factor preventing the
ENC28J60 from being used is that the preprogrammed Microchip TCP/IP Demo
Application has been designed to use the microcontroller’s on-chip Ethernet module.
To use the ENC28J60, the TCP/IP Stack must first be installed so that the source code
may be edited. Once the stack has been installed, consult the TCP/IP Stack Help file
for additional information about reprogramming your board to use the ENC28J60.
may be edited. Once the stack has been installed, consult the TCP/IP Stack Help file
for additional information about reprogramming your board to use the ENC28J60.