Datasheet

3
JP3
JP3, when shorted, will connect the ENC624J600 CLKOUT signal, after level shifting, to the
PICtail connector (J4 Pin 5). If using the PIC18 Explorer, this function may be used to clock
the PIC MCU via the OSC1 input. However, care must be taken to avoid violating the speci-
fications of the Y1 crystal on the PIC18 Explorer. Ideally, the Y1 crystal should be removed,
leaving the crystal soldered on will likely still work, but could force excessive current through
the crystal, potentially damaging it.
Pin 5 of the PICtail Daughter Board interface is not connected on the PICDEM.net 2, so the
state of JP3 will have no impact when using this host board.
If JP3 is left open, the leftmost pin (closest to the ‘C’ in “CLKOUT” on the board silkscreen)
can be used as a convenient test point for measuring or using the ENC624J600 CLKOUT
signal. Note, though, that this signal is level shifted by the U4 buffer, so the peak voltage will
match the VPIC power supply (V_VAR for PIC18 Explorer, +5V for PICDEM.net 2).
The default state of JP3 is open (no jumper shunt).
JP7-JP11
JP7-JP11 control the pinout of the J1 PICtail Plus Daughter Board edge contacts required
for the various Parallel Interface modes. If using the SPI interface, the states of JP7-JP11
are all unimportant. However, to avoid floating the ENC624J600 PSPCFGx input pins, it is
recommended that the JP9-JP11 jumpers have a shunt installed at all times in either the 3V3
or GND configuration.
If using a Parallel Interface mode, set the jumpers according to the desired mode.
Parallel Interface Mode Jumper Settings
For convenient access, this table is also printed on the backside of the Fast 100 Mbps
Ethernet PICtail Plus.
The prior table assumes that Direct Addressing mode is used (all address lines are con-
nected). For Indirect Addressing modes, with a minimal number of address lines connected,
leave the JP7 (PMA to AD) and JP8 (PMA to A) jumpers open.
Since the pinout changes with the different jumper settings, refer to the “Signal Interface”
section for the associated connections that are required.
PSP Mode
PMA
to AD
PMA
to A
PSPCFG1&4 PSPCFG2 PSPCFG3
1 (8-bit) — Short GND GND GND
2 (8-bit)
(1)
— Short 3V3 GND GND
3 (16-bit) — Short GND 3V3 GND
4 (16-bit)
(1)
— Short 3V3 3V3 GND
5 (8-bit MUX) Short — GND GND 3V3
6 (8-bit MUX)
(1)
Short — 3V3 GND 3V3
9 (16-bit MUX) — — GND 3V3 3V3
10 (16-bit MUX)
(1)
— — 3V3 3V3 3V3
Legend: — = open; Short = shunt installed; GND = middle and GND peg shorted;
3V3 = middle and 3V3 peg shorted
Note 1: Do not use PSP Modes 2, 4, 6 or 10 with the Explorer 16. Bus contention
with the Explorer 16 LCD will occur.