| 摘要 |
PURPOSE:To access only a single address to update automatically a physical memory space, by using an optional area of a random access memory as a rotational memory. CONSTITUTION:Optional address data a1 on an RAM1 is latched in a base address determining latch circuit 2 through a data line l1, and optical address data an is latched in a terminating latch circuit 3, thus setting an optional area on the RAM1. A preset counter 4 counts up the address from the base address. That is, a comparator 6 compares contents of the latch circuit 2 with a device address (g); and if the device address is on the set area side more than the base address, a trigger signal (f) is applied to the counter 14 to count up the address, and this counting-up is continued until an output (actual RAM address) (d) of the counter 4 coincides with the terminal address and a reset signal (e) is issued from the comparator 5, and the address is counted up from the base address again after reset. Thus, data is stored rotationally in the memory without intervention of software. |
