DS51795A Datasheet, PDF (91/98 Pages) Microchip Technology – PICkit™ 3 Programmer/Debugger

Glossary
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.
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.
SQTP
See Serialized Quick Turn Programming.
Stack, Hardware
Locations in PIC 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.
© 2009 Microchip Technology Inc.
DS51795A-page 87