User manual

MPLAB
®
REAL ICE
™
In-Circuit Emulator User’s Guide
DS51616B-page 20 © 2008 Microchip Technology Inc.
2.5 TRACE CONNECTIONS
When the emulator is selected as the debug tool, it has several trace capabilities,
depending on the device selected.
2.5.1 Native Trace Connections
No additional connections are necessary to use Native trace. The communications
connection will carry the trace information using the PGD/PGC/EMUC/EMUD pins.
However, the selected device must have this feature. If it does not, one of the other
trace methods may be used.
For more on this type of trace, see Section 7.3.3.1 “Native Trace”.
2.5.2 SPI Trace Connections (High-Speed Communication Only)
When using high-speed communications, streaming serial trace is an optional trace
available using the device SPI and pins 7 (DAT) and 8 (CLK). Figure 2-10 shows these
additional connections. As with pins 4 (PGD) and 5 (PGC) (Section 2.4.4 “Circuits
That Will Prevent the Emulator From Functioning”), do not use pull-up resistors,
capacitors or diodes.
FIGURE 2-10: SERIAL TRACE CONNECTIONS
The DAT and CLK lines are intended for use with devices that do not have built-in
debug logic that allows tracing to use the PGD/PGC/EMUC/EMUD pins. The DAT line
connects to either the target device SPI port SDO1 or SDO2. The CLK line connects to
SCK1 or SCK2.
When you dedicate these pins to tracing, then any multiplexed function on these pins
can no longer be used by the application.
For more on this type of trace, see Section 7.3.3.3 “SPI Trace”.
7
8
Application
PC Board
5
DAT
CLK
Device
SPI
SDO
SCK
High-Speed
Interface
Connector
ACTIVE
STATUS
RESETFUNCTION
Emulator Pod