|
accumulator 音標拼音: [əkj'umjəl ,etɚ] n. 積聚者,蓄能器,蓄電池 積聚者,蓄能器,蓄電池 accumulator累積器; 累加器 AC
accumulator累積器 accumulator累積器 累加器 accumulator n 1: a person who is employed to collect payments ( as for rent or taxes) [ synonym: { collector}, { gatherer}, { accumulator}] 2: a voltaic battery that stores electric charge [ synonym: { storage battery}, { accumulator}] 3: ( computer science) a register that has a built- in adder that adds an input number to the contents of the register [ synonym: { accumulator}, { accumulator register}] Accumulator \ Ac* cu" mu* la` tor\, n. [ L.] 1. One who, or that which, accumulates, collects, or amasses. [ 1913 Webster] 2. ( Mech.) An apparatus by means of which energy or power can be stored, such as the cylinder or tank for storing water for hydraulic elevators, the secondary or storage battery used for accumulating the energy of electrical charges, etc. [ 1913 Webster] 3. A system of elastic springs for relieving the strain upon a rope, as in deep- sea dredging. [ 1913 Webster] In a {central processing unit}, a {register} in
which intermediate results are stored. Without an
accumulator, it would be necessary to write the result of each
calculation (addition, multiplication, {shift}, etc.) to {main
memory} and read them back. Access to main memory is slower
than access to the accumulator which usually has direct paths
to and from the {arithmetic and logic unit} (ALU).
The {canonical} example is summing a list of numbers. The
accumulator is set to zero initially, each number in turn is
added to the value in the accumulator and only when all
numbers have been added is the result written to main memory.
Modern CPUs usually have many registers, all or many of which
can be used as accumulators. For this reason, the term
"accumulator" is somewhat archaic. Use of it as a synonym for
"register" is a fairly reliable indication that the user has
been around for quite a while and/or that the architecture
under discussion is quite old. The term in full is almost
never used of microprocessor registers, for example, though
symbolic names for arithmetic registers beginning in "A"
derive from historical use of the term "accumulator" (and not,
actually, from "arithmetic"). Confusingly, though, an "A"
register name prefix may also stand for "address", as for
example on the {Motorola} {680x0} family.
2. A register, memory location or variable being
used for arithmetic or logic (as opposed to addressing or a
loop index), especially one being used to accumulate a sum or
count of many items. This use is in context of a particular
routine or stretch of code. "The FOOBAZ routine uses A3 as an
accumulator."
[{Jargon File}]
(1999-04-20)
|
安裝中文字典英文字典查詢工具!
中文字典英文字典工具:
英文字典中文字典相關資料:
|