Self-checking microprogram control unit with on-line error detection capability, in mos technology

Abstract From the Canadian patent

A self checking microprogram control unit detects errors concurrently with normal micro-instruction execution through internal checking circuits and a particular microinstruction configuration in memory. Micro-instructions comprise additional fields carrying the encoding in, modified Berger code, of the address of the microinstruction itself and of the following micro-instruction; micro-instructions which are the destination of conditional jumps are located so that their codes are related to each other by simple logic relationships which are reproduced by an internal circuit; the two fields from this and the following micro-instructions which relate to the same micro-instruction are then …