Cyclone System Board Manual
16550 UART
- A high speed chip for
controlling serial ports. Although un-
necessary for a mouse, it is required for
modems that are 14,400 baud or faster.
APM
- An acronym for Advanced
Power Management.
The APM speci-
fication defines a layer of software
that supports power management
in computers with power manage-
able hardware.
Asynchronous
- Operations that do
not require the clocks of communicat-
ing devices to be coordinated. See Syn-
chronous.
Bidirectional Parallel Port
- A type of
parallel port that can send and receive
information.
BIOS
- An Acronym for Basic Input/
Output System. Configures the system
board and provides hardware informa-
tion to the operating system.
Bit
- A contraction of Binary digit.
The smallest unit of information in a
binary number system. A bit repre-
sents a choice between either zero or
one.
Boot
- To start up the computer and
load the operating system software. See
cold boot and warm boot.
Bus
- A group of electronic paths used
to send data between parts of the sys-
tem. On a system board, the bus con-
nects the peripheral cards with the mi-
croprocessor via the expansion slots.
Glossary
Glossary
66
Bus Mastering
- The ability of a
peripheral card to control the bus with-
out requiring intervention of the CPU.
Byte
- A group of adjacent bits treated
as a unit. Eight bits are typically con-
sidered one byte. Also called a charac-
ter.
Cache
- A process where information
is copied from the slower memory
(DRAM) to the faster memory
(SRAM). Information that is likely to
be read or edited is stored in the cache
providing significant performance in-
creases.
Cache Hit
- The percentage of request
for data from memory that can be
served from the cache.
Cache Miss
- A memory access which
cannot be supplied from cache.
Cold Boot
- Starting the computer by
turning on the power or pressing the
RESET button. A cold boot makes the
processor execute all of the diagnostics.
See boot and warm boot.
CPU
- An acronym for Central Pro-
cessing Unit. A CPU performs arith-
metic calculations, makes logical
decisions, and directs the operation of
the computer in conjunction with the
operating system.
DIMM
- An acronym for Dual Inline
Memory Module. A small printed cir-
cuit board containing memory chips.
