Motorola 68000

52
The 68000's Instruction Set
Attributes: Unsized
Description: The immediate operand is copied into the entire status register
(i.e., both status byte and CCR are modified), and the program
counter advanced to point to the next instruction to be executed.
The processor then suspends all further processing and halts.
That is, the privileged STOP instruction stops the 68000.
The execution of instructions resumes when a trace, an interrupt,
or a reset exception occurs. A trace exception will occur if the
trace bit is set when the STOP instruction is encountered. If an
interrupt request arrives whose priority is higher than the current
processor priority, an interrupt exception occurs, otherwise the
interrupt request has no effect. If the bit of the immediate data
corresponding to the S-bit is clear (i.e., user mode selected),
execution of the STOP instruction will cause a privilege violation.
An external reset will always initiate reset exception processing.
Condition codes: X N Z V C
* * * * *
Set according to the literal.
SUB Subtract binary
Operation: [destination] ← [destination] - [source]
Syntax: SUB <ea>,Dn
SUB Dn,<ea>
Attributes: Size = byte, word, longword
Description: Subtract the source operand from the destination operand and
store the result in the destination location.
Condition codes: X N Z V C
* * * * *
Source operand addressing modes