LSI LSI21002, Руководство пользователя

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Glossary B-5
PIO Programmed Input/Output. A way the CPU can transfer data to and from
memory using the computer’s I/O ports. PIO can be faster than DMA, but
requires CPU time.
Port Address Also Port Number. The address through which commands are sent to a
host adapter board. This address is assigned by the PCI bus.
Port Number See Port Address.
Queue Tags A way to keep track of multiple commands that allows for increased
throughput on the SCSI bus.
RAM Random Access Memory. Generally, the computer’s primary working
memory in which program instructions and data are stored and are
accessible to the CPU. Information can be written to and read from RAM.
The contents of RAM are lost when the computer is turned off.
RISC Core Some SCSI chips contain a RISC (Reduced Instruction Set Computer)
processor, programmed through microcode scripts.
ROM Read Only Memory. Memory from which information can be read but not
changed. The contents of ROM are not erased when the computer is
turned off.
SCAM SCSI Configured Automatically. A method to automatically allocate SCSI
IDs via software when SCAM compliant SCSI devices are attached.
SCSI Small Computer System Interface. A specification for a high performance
peripheral bus and command set. The original standard is now referred
to as SCSI-1.
SCSI-2 The current SCSI specification which adds features to the original
SCSI-1 standard.
SCSI-3 The next SCSI specification, which adds features to the SCSI-2 standard.
SCSI Bus A host adapter and one or more SCSI peripherals connected by cables
in a linear chain configuration. The host adapter may exist anywhere on
the chain, allowing connection of both internal and external SCSI
devices. A system may have more than one SCSI bus by using multiple
host adapters.