Philips Semiconductors

LPC2114/LPC2124

Single-chip 16/32-bit microcontrollers

Product data

Rev. 03 — 22 December 2004

24 of 34

9397 750 13145

© Koninklijke Philips Electronics N.V. 2004. All rights reserved.

6.20.1

Embedded ICE™

Standard ARM EmbeddedICE logic provides on-chip debug support. The debugging

of the target system requires a host computer running the debugger software and an

EmbeddedICE protocol convertor. EmbeddedICE protocol convertor converts the

Remote Debug Protocol commands to the JTAG data needed to access the ARM

core.

The ARM core has a Debug Communication Channel function built-in. The debug

communication channel allows a program running on the target to communicate with

the host debugger or another separate host without stopping the program flow or

even entering the debug state. The debug communication channel is accessed as a

co-processor 14 by the program running on the ARM7TDMI-S core. The debug

communication channel allows the JTAG port to be used for sending and receiving

data without affecting the normal program flow. The debug communication channel

data and control registers are mapped in to addresses in the EmbeddedICE logic.

6.20.2

Embedded trace

Since the LPC2114/LPC2124 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.

6.20.3

RealMonitor

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 (Debug Communications Channel), which is present in the EmbeddedICE

logic. The LPC2114/LPC2124 contain a specific configuration of RealMonitor

software programmed into the on-chip Flash memory.