Computing device having instructions which access either a permanently fixed default memory bank or a memory bank specified by an immediately preceding bank selection instruction

摘要

A computing device accesses multiple memory banks, which are selected by a bank selection instruction. The memory bank selected by the bank selection instruction is accessed by a memory access instruction immediately following the bank selection instruction. Following any instruction other than the bank selection instruction, a default memory bank is selected automatically. This scheme eliminates the need to select the default memory bank explicitly, and the need to save and restore the contents of a bank selection register when interrupts are served.