Address generating circuit for generating addresses separated by a prescribed step value in circular addressing

摘要

An address generating circuit of simple configuration for circular addressing. A bit isolating circuit 304 extracts an index from an input address. When a step value input to an adder 302 is positive, an index generating circuit subtracts the sum of the index and step value from a block size of a memory region. Depending on the subtraction result, an output which is either the sum of the index and step value or the subtraction result is provided as a new index. When the step value is negative, the index and step value are added. Depending on the addition result, an output which is either the sum of the index, step value, and capacity of the memory region or the addition result is provided as a new index. A bit multiplexer 314 generates the next address from the new index and an address.