i.MX25 PDK Linux Reference Manual
Freescale Semiconductor -19
ISR Interrupt Service Routine
JT
AG JTAG (IEEE Standard 1149.1) A standard specifying how to control and monitor the pins of compliant devices
on a printed circuit board
Kill Abort a memory access
KPP KeyPad Port—16-bit peripheral used as a keypad matrix interface or as general purpose input/output (I/O)
line Refers to a unit of information in the cache that is associated with a tag
LRU Least Recently Used—a policy for line replacement in the cache
MMU Memory Management Unit—a component responsible for memory protection and address translation
MPEG Moving Picture Experts Group—an ISO committee that generates standards for digital video compression and
audio. It is also the name of the algorithms used to compress moving pictures and video
MPEG
standards
There are several standards of compression for moving pictures and video
• MPEG-1 is optimized for CD-ROM and is the basis for MP3
• MPEG-2 is defined for broadcast video in applications such as digital television set-top boxes and DVD
• MPEG-3 was merged into MPEG-2
• MPEG-4 is a standard for low-bandwidth video telephony and multimedia on the World-Wide Web
MQSPI Multiple Queue Serial Peripheral Interface—used to perform serial programming operations necessary to
configure radio subsystems and selected peripherals
MSHC Memory Stick Host Controller
NAND Flash Flash ROM technology—NAND Flash architecture is one of two flash technologies (the other being NOR) used
in memory cards such as the Compact Flash cards. NAND is best suited to flash devices requiring high capacity
data storage. NAND flash devices offer storage space up to 512-Mbyte and offers faster erase, write, and read
capabilities over NOR architecture
NOR Flash See NAND Flash
PCMCIA Personal Computer Memory Card International Association—a multi-company organization that has developed
a standard for small, credit card-sized devices, called PC Cards. There are three types of PCMCIA cards that
have the same rectangular size (85.6 by 54 millimeters), but different widths
physical
address
The address by which the memory in the system is physically accessed
PLL Phase Locked Loop—an electronic circuit controlling an oscillator so that it maintains a constant phase angle
(a lock) on the frequency of an input, or reference, signal
RAM Random Access Memory
RAM path Path within ROM bootstrap leading to the downloading and the execution of a RAM application
RGB The RGB color model is based on the additive model in which Red, Green, and Blue light are combined to create
other colors. The abbreviation RGB come from the three primary colors in additive light models
RGBA RGBA color space stands for Red Green Blue Alpha. The alpha channel is the transparency channel, and is
unique to this color space. RGBA, like RGB, is an additive color space, so the more of a color placed, the lighter
the picture gets. PNG is the best known image format that uses the RGBA color space
RNGA Random Number Generator Accelerator—a security hardware module that produces 32-bit pseudo random
numbers as part of the security module
ROM Read Only Memory
Definitions and Acronyms (continued)
Term Definition