JPS6488840A - Data processor - Google Patents

Abstract

PURPOSE:To quickly perform repeated processing by storing and holding a decoded result at the time of first decoding an instruction to be repeatedly processed and using the stored and held the decoded result to perform the repeated processing. CONSTITUTION:When a transfer instruction is read out from a memory 3 by an address, for example, an address 100 given from a program counter 1, the transfer instruction is decoded by a decoder 4. When decoding is terminated, the instruction length of the transfer instruction is added to an adder 2, and contents of the counter 1 are updated to 102. The decoded result is processed by an executing unit 5. The instruction in address 102 is processed in the same manner and contents of the counter 1 are updated to 104. When the instruction in address 104 is decoded, a storage pointer 7 is cleared and contents of the counter 1 are updated to 105. When the instruction in address 105 is decoded, the decoded result is sent to the unit 5 and is stored in a decode buffer 6. When the instruction in address 108 is processed thereafter, contents of the buffer 6 are sent to the unit 5.