CHAPTER 4 BUS CONTROL FUNCTION
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4.10 Memory Boundary Operation Conditions
4.10.1 Program space
(1) Do not execute a branch to the on-chip peripheral I/O area or continuous fetch from the internal RAM area to the
peripheral I/O area. If a branch or instruction fetch is executed, the NOP instruction code is continuously fetched
and no data is fetched from external memory.
(2) A prefetch operation straddling over the on-chip peripheral I/O area (invalid fetch) does not take place if a branch
instruction exists at the upper-limit address of the internal RAM area.
4.10.2 Data space
Only the address aligned at the halfword boundary (when the least significant bit of the address is “0”)/word
boundary (when the lowest 2 bits of the address are “0”) boundary is accessed by halfword (16 bits)/word (32 bits)
data.
Therefore, access that straddles over the memory or memory block boundary does not take place.
For details, refer to
V850 Series Architecture User’s Manual
.