LPC2220 PHILIPS [NXP Semiconductors], LPC2220 Datasheet - Page 30

• Manufacturer Part Number: LPC2220
• Description: 16/32-bit ARM microcontrollers; flashless with 64 kB, with 10-bit ADC and external memory interface
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
9397 750 14061
Product data sheet
6.21.2 Embedded trace
6.21.3 RealMonitor
Since the LPC2210/2220 has 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 (ETM) 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 cannot 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 Debug
Communications Channel (DCC), which is present in the EmbeddedICE logic. The
LPC2210/2220 contains a specific configuration of RealMonitor software programmed into
the on-chip memory.
16/32-bit ARM microcontrollers with external memory interface
Rev. 02— 30 May 2005
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
LPC2210/2220
30 of 49