| 摘要 |
PURPOSE:To easily execute access protecting processing by generating a non maskable interrupt and jumping to an address registered in an NMI (Non Maskable Interrupt) register when a program generates an access contravention. CONSTITUTION:When the title microprocessor starts its memory access cycle, a comparator 7 compares an access address to be sent from an address generator 6 with the contents of an area upper limit register 2, and when the address is <= the contents, the comparator 7 compares the address with the contents of an area lower limit register 3. As the result, when the address is >= a lower limit value indicated in the area lower limit register 3, the comparator 7 sends a signal to indicate the occurrence of an address inhibition contravention to an NMI controller 9. At this time, the non maskable interrupt is generated, memory access is not actually executed, and jumping to the address registered in an NMI register 4 is executed. Thus, access can be easily protected. |
