User manual

MPLAB
®
REAL ICE
™
In-Circuit Emulator User’s Guide
DS51616B-page 136 © 2008 Microchip Technology Inc.
Recursion
The concept that a function or macro, having been defined, can call itself. Great care
should be taken when writing recursive macros; it is easy to get caught in an infinite
loop where there will be no exit from the recursion.
ROM
Read Only Memory (Program Memory). Memory that cannot be modified.
Run
The command that releases the emulator from halt, allowing it to run the application
code and change or respond to I/O in real time.
Scenario
For MPLAB SIM simulator, a particular setup for stimulus control.
Sequenced Breakpoints
Breakpoints that occur in a sequence. Sequence execution of breakpoints is
bottom-up; the last breakpoint in the sequence occurs first.
SFR
See Special Function Registers.
Shell
The MPASM assembler shell is a prompted input interface to the macro assembler.
There are two MPASM assembler shells: one for the DOS version and one for the
Windows version.
Simulator
A software program that models the operation of devices.
Single Step
This command steps though code, one instruction at a time. After each instruction,
MPLAB IDE updates register windows, watch variables, and status displays so you can
analyze and debug instruction execution. You can also single step C compiler source
code, but instead of executing single instructions, MPLAB IDE will execute all assembly
level instructions generated by the line of the high level C statement.
Skew
The information associated with the execution of an instruction appears on the proces-
sor bus at different times. For example, the executed opcodes appears on the bus as
a fetch during the execution of the previous instruction, the source data address and
value and the destination data address appear when the opcodes is actually executed,
and the destination data value appears when the next instruction is executed. The trace
buffer captures the information that is on the bus at one instance. Therefore, one trace
buffer entry will contain execution information for three instructions. The number of cap-
tured cycles from one piece of information to another for a single instruction execution
is referred to as the skew.
Skid
When a hardware breakpoint is used to halt the processor, one or more additional
instructions may be executed before the processor halts. The number of extra
instructions executed after the intended breakpoint is referred to as the skid.
Source Code
The form in which a computer program is written by the programmer. Source code is
written in a formal programming language which can be translated into machine code
or executed by an interpreter.