User manual

Glossary
© 2008 Microchip Technology Inc. DS51616B-page 131
A higher data transfer rate means fewer wires are required, as in UW (Ultra Wide) and
UW-2/3 SCSI hard disks, which use only 68 wires. These devices require a high trans-
fer rate over short distances. Using standard I/O transfer, SCSI hard drives would
require a lot more than 68 wires.
Low voltage means that the standard 5 volts is replaced by either 3.3 volts or 1.5 volts.
LVDS uses a dual wire system, running 180 degrees of each other. This enables noise
to travel at the same level, which in turn can get filtered more easily and effectively.
With standard I/0 signaling, data storage is contingent upon the actual voltage level.
Voltage level can be affected by wire length (longer wires increase resistance, which
lowers voltage). But with LVDS, data storage is distinguished only by positive and neg-
ative voltage values, not the voltage level. Therefore, data can travel over greater
lengths of wire while maintaining a clear and consistent data stream.
Source: http://www.webopedia.com/TERM/L/LVDS.html.
Machine Code
The representation of a computer program that is actually read and interpreted by the
processor. A program in binary machine code consists of a sequence of machine
instructions (possibly interspersed with data). The collection of all possible instructions
for a particular processor is known as its “instruction set”.
Machine Language
A set of instructions for a specific central processing unit, designed to be usable by a
processor without being translated.
Macro
Macro instruction. An instruction that represents a sequence of instructions in abbrevi-
ated form.
Macro Directives
Directives that control the execution and data allocation within macro body definitions.
Makefile
Export to a file the instructions to Make the project. Use this file to Make your project
outside of MPLAB IDE, i.e., with a make.
Under Project>Build Options>Project
, Directories tab, you must have selected
“Assemble/Compile/Link in the project directory” under “Build Directory Policy” for this
feature to work.
Make Project
A command that rebuilds an application, recompiling only those source files that have
changed since the last complete compilation.
MCU
Microcontroller Unit. An abbreviation for microcontroller. Also uC.
Message
Text displayed to alert you to potential problems in language tool operation. A message
will not stop operation.
Microcontroller
A highly integrated chip that contains a CPU, RAM, program memory, I/O ports and
timers.
Microcontroller Mode
One of the possible program memory configurations of PIC17 and PIC18 microcon-
trollers. In microcontroller mode, only internal execution is allowed. Thus, only the
on-chip program memory is available in microcontroller mode.