Microchip Technology AC244006 Manuel D’Utilisation
Operation
© 2006 Microchip Technology Inc.
DS51616A-page 15
Not all devices have the AV
DD
and AV
SS
lines, but if they are present on the target
device, all must be connected to the appropriate levels in order for the emulator to
operate.
The interconnection is very simple; any problems experienced are often caused by
other connections or components on these critical lines that interfere with the operation
of the MPLAB REAL ICE in-circuit emulator system, as discussed in the next section.
operate.
The interconnection is very simple; any problems experienced are often caused by
other connections or components on these critical lines that interfere with the operation
of the MPLAB REAL ICE in-circuit emulator system, as discussed in the next section.
2.5.4
Circuits That Will Prevent the Emulator From Functioning
Figure 2-9 shows the active emulator lines with some components that will prevent the
MPLAB REAL ICE in-circuit emulator system from functioning.
MPLAB REAL ICE in-circuit emulator system from functioning.
FIGURE 2-9:
IMPROPER CIRCUIT COMPONENTS
Specifically, these guidelines must be followed:
• No pull-ups on PGC/PGD – they will divide the voltage levels, since these lines
• No pull-ups on PGC/PGD – they will divide the voltage levels, since these lines
have 4.7 k
Ω pull-down resistors in the emulator.
• No capacitors on PGC/PGD – they will prevent fast transitions on data and clock
lines during programming and debug communications.
• No capacitors on MCLR – they will prevent fast transitions of V
PP
. A simple pull-up
resistor is generally sufficient.
• No diodes on PGC/PGD – they will prevent bidirectional communication between
the emulator and the target device.
No!
No!
No!
No!
V
PP
/MCLR
PGC
PGD
1
5
4
MPLAB
®
REAL
ICE™
In-Circuit
Emulator
ICE™
In-Circuit
Emulator
Interface
Connector