LPC2131 Philips Semiconductors (Acquired by NXP), LPC2131 Datasheet - Page 25

• Manufacturer Part Number: LPC2131
• Manufacturer: Philips Semiconductors (Acquired by NXP)

Philips Semiconductors
9397 750 14008
Preliminary data sheet
6.22.2 Embedded trace
6.22.3 RealMonitor
Since the LPC2131/2132/2138 have significant amounts of on-chip memory, it is not
possible to determine how the processor core is operating simply by observing the
external pins. The Embedded Trace Macrocell™ provides real-time trace capability for
deeply embedded processor cores. It outputs information about processor execution to
the trace port.
The ETM is connected directly to the ARM core and not to the main AMBA system bus. It
compresses the trace information and exports it through a narrow trace port. An external
trace port analyzer must capture the trace information under software debugger control.
Instruction trace (or PC trace) shows the flow of execution of the processor and provides a
list of all the instructions that were executed. Instruction trace is significantly compressed
by only broadcasting branch addresses as well as a set of status signals that indicate the
pipeline status on a cycle by cycle basis. Trace information generation can be controlled
by selecting the trigger resource. Trigger resources include address comparators,
counters and sequencers. Since trace information is compressed the software debugger
requires a static image of the code being executed. Self-modifying code can not be traced
because of this restriction.
RealMonitor is a configurable software module, developed by ARM Inc., which enables
real time debug. It is a lightweight debug monitor that runs in the background while users
debug their foreground application. It communicates with the host using the DCC, which is
present in the EmbeddedICE logic. The LPC2131/2132/2138 contain a specific
configuration of RealMonitor software programmed into the on-chip Flash memory.
Rev. 01 — 18 November 2004
LPC2131/2132/2138
Single-chip 16/32-bit microcontrollers
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
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