LPC2292 datasheet(28/53 Pages) NXP

28 / 53 page

LPC2292_2294_7

Product data sheet

Rev. 7 — 4 December 2008

28 of 53

NXP Semiconductors

LPC2292/LPC2294

16/32-bit ARM microcontrollers with external memory interface

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.

The JTAG clock (TCK) must be slower than 1

⁄

6 of the CPU clock (CCLK) for the JTAG

interface to operate.

6.20.2 Embedded trace

Since the LPC2292/LPC2294 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 cannot 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 Debug

Communications Channel (DCC), which is present in the EmbeddedICE logic. The

LPC2292/LPC2294 contain a speciﬁc conﬁguration of RealMonitor software programmed

into the on-chip ﬂash memory.

LPC2292 Datasheet(PDF) 28 Page - NXP Semiconductors