Search results
Results From The WOW.Com Content Network
In a computer's central processing unit (CPU), the accumulator is a register in which intermediate arithmetic logic unit results are stored.. Without a register like an accumulator, it would be necessary to write the result of each calculation (addition, multiplication, shift, etc.) to cache or main memory, perhaps only to be read right back again for use in the next operation.
The accumulator can be viewed as a truncated rate 1 recursive convolutional encoder with transfer function / (+), but Divsalar et al. prefer to think of it as a block code whose input block (, …,) and output block (, …,) are related by the formula = and = + for >.
add the contents of a memory cell to the accumulator. 3: TAC: Test accumulator contents performs a sign test on the contents of the accumulator; if minus, jump to a specified memory cell. 4: SFT: Shift shifts the accumulator x places left, then y places right, where x is the upper address digit and y is the lower. 5: OUT: Output
ENIAC was a large, modular computer, composed of individual panels to perform different functions. Twenty of these modules were accumulators that could not only add and subtract, but hold a ten-digit decimal number in memory. Numbers were passed between these units across several general-purpose buses (or trays, as they were called). In order ...
In 1967, Fairchild introduced the first ALU-like device implemented as an integrated circuit, the Fairchild 3800, consisting of an eight-bit arithmetic unit with accumulator. It only supported adds and subtracts but no logic functions. [7] Full integrated-circuit ALUs soon emerged, including four-bit ALUs such as the Am2901 and 74181.
The hardware unit that performs the operation is known as a multiplier–accumulator (MAC unit); the operation itself is also often called a MAC or a MAD operation. The MAC operation modifies an accumulator a : a ← a + ( b × c ) {\displaystyle a\gets a+(b\times c)}
For example, MOVW copies the value of W to the destination. When used with d = 1, this stores W to f . There is a matching MOVF instruction which outputs the value of f .
More practical accumulators use a quasi-commutative hash function, so that the size of the accumulator does not grow with the number of members. For example, Benaloh and de Mare propose a cryptographic accumulator inspired by RSA : the quasi-commutative function h ( x , y ) := x y ( mod n ) {\displaystyle h(x,y):=x^{y}{\pmod {n}}} for some ...