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MB90420/5 (A) SERIES F
2.9 Prefix Codes
When an instruction is prefixed by a code, the operation of the instruction can be changed partially.
Following three types of prefix code are available:
• Bank select prefix (PCB, DTB, ADB, and SPB)
• Common register bank prefix (CMR)
• Flag change inhibit prefix (NCC)
n Prefix code
• Bank select prefix (PCB, DTB, ADB, and SPB)
When an instruction is prefixed by a bank select prefix, the memory space accessed by the instruction can
be selected arbitrarily irrespective of the addressing type.
• Common register bank prefix (CMR)
When an instruction that accesses the register bank is prefixed by a common register bank prefix, all the
access destination of the instruction can be changed to the common bank at 000180
common bank is the register bank selected when RP=0), irrespective of the value of the current register
bank pointer (RP).
• Flag change inhibit prefix (NCC)
When the flag change inhibit instruction is prefixed by the flag change inhibit prefix code, the flag change
caused by execution of the instruction can be inhibited.
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MC-16LX FAMILY 16-BIT MICROCONTROLLERS HARDWARE MANUAL
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