Datasheet
Specific Debug Functions: 8- and 16-Bit Devices
2013 Microchip Technology Inc. DS52085A-page 57
6.3.3 Types of Trace
Currently there are three types of trace. All types are language tool version dependent,
and stream data in real time to MPLAB IDE.
The pluses and minuses of using each trace type, as well as the type of communication
available (standard and/or high-speed), are summarized below.
6.3.3.1 NATIVE TRACE
Native trace can be used with either standard or high-speed communications, with no
additional connections - the information is conveyed via the PGD/PGC/EMUC/EMUD
pins. This two-wire interface uses the trace macro format (see Section 6.3.4 “Setting
Up Trace in MPLAB IDE”).
Native trace requires that you enter the clock speed (Properties dialog, REAL ICE
category, Clock options category.)
If Native trace is used, then data captures cannot be used as these features use the
same device resource. Breakpoints are still available but be aware that Native trace will
use one breakpoint for tracing. This will NOT be reflected on the Device Debug
Resource toolbar.
To use data capture triggers, you must disable Native trace (see
Section 6.3.7 “Disabling Trace”).
6.3.3.2 SPI TRACE
SPI trace can be used only with high-speed communication hardware (LVDS cables).
Trace clock and data are provided through pins 7 (DAT) and 8 (CLK) on the receiver
board of the LVDS connection. The device does not have to be operating at high
speeds to use this feature.
For devices with remappable peripheral pins, be aware that the SPI trace macro does
not touch any PPS register and does not need to know how the peripheral is mapped
to a certain pin - it will write to the SPI1 or SPI2 selected in MPLAB IDE.
SPI trace does require that you enter the clock speed (Properties dialog, REAL ICE
category, Clock options category.)
For hardware connections, see Section 3.6.2 “SPI Trace Connections
(High-Speed/LVDS Connection)”.
The SPI interface uses the trace macro format (see Section 6.3.4 “Setting Up Trace
in MPLAB IDE”).
Type of
Trace
Speed
Code
Size
Impact
Real
Time
Op
Pin
Usage
Device
Feature
Needed
Communication
Std HS
Native Trace Fast
(1)
Large Close None Built-in
debug
15 MIPS
or less
Greater than
15 MIPS
SPI Trace Faster
(1)
Medium Closer SPI
pins
SPI No Yes
I/O Port Trace Fastest Small Closest 8-pin
port
None Yes
(2)
Yes
(2)
Note 1: For Native trace running at speeds higher than 15 MIPS and for SPI Trace capabil-
ity, the Performance Pak may be needed. The actual cutoff speed may vary
depending on layout, noise, and similar considerations.
Note 2: Also requires connection from device port to emulator logic probe port.