LPC2148 Philips, LPC2148 Datasheet - Page 27

• Manufacturer Part Number: LPC2148
• Description: 16/32 Bit Microcontroller
• Manufacturer: Philips

Philips Semiconductors
9397 750 14985
Preliminary data sheet
6.23.1 EmbeddedICE
6.23.2 Embedded trace
6.23.3 RealMonitor
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 (DCC) function built-in. The DCC
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
DCC is accessed as a co-processor 14 by the program running on the ARM7TDMI-S
core. The DCC allows the JTAG port to be used for sending and receiving data without
affecting the normal program flow. The DCC data and control registers are mapped in to
addresses in the EmbeddedICE logic.
Since the LPC2142/2148 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 (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 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 LPC2142/2148 contain a specific configuration of
RealMonitor software programmed into the on-chip flash memory.
Rev. 01 — 22 June 2005
Single-chip 16/32-bit microcontrollers
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
LPC2142/2148
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