User`s guide

Glossary
© 2006 Microchip Technology Inc. DS51519B-page 269
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 instruc-
tions 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 some formal programming language which can be translated into or machine
code or executed by an interpreter.
Source File
An ASCII text file containing source code.
Special Function Registers
The portion of data memory (RAM) dedicated to registers that control I/O processor
functions, I/O status, timers or other modes or peripherals.
Stack, Hardware
Locations in PICmicro microcontroller where the return address is stored when a
function call is made.
Stack, Software
Memory used by an application for storing return addresses, function parameters and
local variables. This memory is typically managed by the compiler when developing
code in a high-level language.
Static RAM or SRAM
Static Random Access Memory. Program memory you can Read/Write on the target
board that does not need refreshing frequently.
Status Bar
The Status Bar is located on the bottom of the MPLAB IDE window and indicates such
current information as cursor position, development mode and device and active tool
bar.
Step Into
This command is the same as Single Step. Step Into (as opposed to Step Over) follows
a CALL instruction into a subroutine.
Step Over
Step Over allows you to step over subroutines. This command executes the code in the
subroutine and then stops execution at the return address to the subroutine.
When stepping over a CALL instruction, the next breakpoint will be set at the instruction
after the CALL. If for some reason the subroutine gets into an endless loop or does not
return properly, the next breakpoint will never be reached. Select Halt to regain control
of program execution.
Step Out
Step Out allows you to step out of a subroutine which you are currently stepping
through. This command executes the rest of the code in the subroutine and then stops
execution at the return address to the subroutine.
Stimulus
Input to the simulator, i.e., data generated to exercise the response of simulation to
external signals. Often the data is put into the form of a list of actions in a text file. Stim-
ulus may be asynchronous, synchronous (pin), clocked and register.
Stopwatch
A counter for measuring execution cycles.