User manual

Glossary
ARM DDI0198D Copyright © 2001-2003 ARM Limited. All rights reserved. Glossary-11
Fully-associative cache
A cache that has just one cache set that consists of the entire cache. The number of cache
entries is the same as the number of cache ways.
See also Direct-mapped cache.
Half-rate clocking (ETM)
Dividing the trace clock by two so that the TPA can sample trace data signals on both
the rising and falling edges of the trace clock. The primary purpose of half-rate clocking
is to reduce the signal transition rate on the trace clock of an ASIC for very high-speed
systems.
Halfword A 16-bit data item.
Halt mode One of two mutually exclusive debug modes. In halt mode all processor execution halts
when a breakpoint or watchpoint is encountered. All processor state, coprocessor state,
memory and input/output locations can be examined and altered by the JTAG interface.
See also Monitor debug-mode.
High vectors Alternative locations for exception vectors. The high vector address range is near the
top of the address space, rather than at the bottom.
Host A computer that provides data and other services to another computer. Especially, a
computer providing debugging services to a target being debugged.
ICache A block of on-chip fast access memory locations, situated between the processor and
main memory, used for storing and retrieving copies of often used instructions. This is
done to greatly reduce the average speed of memory accesses and so to increase
processor performance.
IGN See Ignore.
Ignore (IGN) Must ignore memory writes.
Illegal instruction An instruction that is architecturally Undefined.
IMB See Instruction Memory Barrier.
Implementation-defined
Means that the behavior is not architecturally defined, but should be defined and
documented by individual implementations.
Implementation-specific
Means that the behavior is not architecturally defined, and does not have to be
documented by individual implementations. Used when there are a number of
implementation options available and the option chosen does not affect software
compatibility.