1989_MELPS_7700_Software_Manual

Absolute Indexed X Indirect
Mode
Function
Absolute indexed X indirect addressing mode
The value obtained by adding the instruction's second and third bytes and the contents
of the index register X specifies 2 adjacent bytes in memory, and the contents
of these bytes specify the address to which a jump is to be made.
Instruction: JMP, JSR
ex.
: Mnemonic
JMP(1234H, X)
(x=1)
Machine Code
7C '6 34 '6 12 '6
-
Memory
-------
Index
Register X
246,.= 1 : 12,·1 + {
Op Code (7C,.)
Operand (34,.)
Operand (12,.)
DATA I (12,.)
DATA II (BC,.)
1246,.
}
Program
bank-PG
Address to be
executed next
-------
-
Program
Bank Register
~BC12,.
39