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The 68000's Instruction Set
Syntax: JSR <ea>
Attributes: Unsized
Description: JSR pushes the longword address of the instruction immediately
following the JSR onto the system stack. Program execution then
continues at the address specified in the instruction.
Application: JSR (Ai) calls the procedure pointed at by address register Ai.
The instruction JSR (Ai,Dj) calls the procedure at the location
[Ai]+[Dj] which permits dynamically computed addresses.
Condition codes: X N Z V C
- - - - -
Source operand addressing modes
LEA Load effective address
Operation: [An] ← <ea>
Syntax: LEA <ea>,An
Sample syntax: LEA Table,A0
LEA (Table,PC),A0
LEA (-6,A0,D0.L),A6
LEA (Table,PC,D0),A6
Attributes: Size = longword
Description: The effective address is computed and loaded into the specified
address register. For example, LEA (-6,A0,D0.W),A1 calculates
the sum of address register A0 plus data register D0.W sign-
extended to 32 bits minus 6, and deposits the result in address
register A1. The difference between the LEA and PEA instructions
is that LEA calculates an effective address and puts it in an ad-
dress register, while PEA calculates an effective address in the
same way but pushes it on the stack.
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