Direct addressing means the instruction
refers directly to the address being accessed. That is, the instruction
encoding itself contains the address of the location. Depending on the
instruction set, it may also allow computing a small index relative to
the address. When used that way, you can think of that as a
direct-indexed mode. (Note: Some processors call ‘direct’ mode
‘absolute’, such as the 6502.)
Indirect addressing uses an address held in a register or other location to determine what memory location to read or write. The idea here is that the instruction itself isn’t directly telling you the address to access, but rather indirectly telling the CPU where to find that address. The processor may also allow you to add a small offset to the indirect address, giving an indirect-indexed addressing mode.
Also Read : 5 Best Terminal Emulators for Linux The 6502 one is a little quirky: The 6502 doesn’t have general-purpose registers large enough to store addresses, so i…
Indirect addressing uses an address held in a register or other location to determine what memory location to read or write. The idea here is that the instruction itself isn’t directly telling you the address to access, but rather indirectly telling the CPU where to find that address. The processor may also allow you to add a small offset to the indirect address, giving an indirect-indexed addressing mode.
Also Read : 5 Best Terminal Emulators for Linux The 6502 one is a little quirky: The 6502 doesn’t have general-purpose registers large enough to store addresses, so i…
Comments
Post a Comment