摘要 |
PURPOSE:To make the control of a loop simple and to prevent the reduction of a bus efficiency by adding an easy hardware and executing a multiple DO control. CONSTITUTION:By adding, further, two registers 101 and 102 to a usual stack 104, the information for processing two loops can be stored. AT one side register 102 out of two added registers, an exclusive-use subtracter 103 is provided, and is an exclusive-use register equivalent to a loop counting register. Other register 101 is the exclusive-use register to store the return address for the loop. The stack 104 and two added registers 101 and 102 are interlocked, operated as the stack of LIFO constitution and two subtracting mode and bus mode are held for a subtracter 103. |