JPS6469135A - Time division multiplexing device - Google Patents

Abstract

PURPOSE:To simplify a hardware and to decrease a cost by using a dual port RAM as assigning table part. CONSTITUTION:For an assigning table part, a dual port RAM 20 is used, one side port of the dual port RAM 20 can access the writing and reading from a control part 4 to execute the re-writing and reading of the contents of an assigning table and other side is set so as to be able to execute only the reading. When the writing command of one side port is executed, an address given to respective ports is compared by a comparing means, when the value of both is coincident, the priority is given to one side port side and the output to a data bus 2 of address information is prohibited. Thus, since the access from a control part side can be executed without giving an influence to an inherent output action for the assigning table part and the hardware constitution can be simplified, the cost can be decreased.