摘要 |
PURPOSE:To reduce steps in number with the bit length of an IMD made variable by equipping a CPU on a microprogram-stored control system with a bus through which immediate data IMD is transmitted to a desirable bit position. CONSTITUTION:The CPU is provided with micro-data register MRDR registering microprogram muPG; some of the contents of it is for a control field, and the other is sent out to A-BUS as IMD. Bits 19 to 21 of MRDR are used for the assignment of the bit position of A-BUS for a number sisplayed in the DATA field of the FI field. For example, when bits 19 to 21 of the FI field are supposed to be ''001'', gate G2 is opened by a timing signal and the number of the DATA field is transmitted to bits 14 to 23 of A-BUS. Therefore, since the transmission bit position of IMD becomes variable, flexibility is given to the control, the bit length of IMD can be elongated, and steps of muPG can also be reduced in number, so that the arithmetic speed will become high. |