Contents | < Browse | Browse >
NAME
CMP -- Compare
SYNOPSIS
CMP <ea>,Dn
Size = (Byte, Word, Long)
FUNCTION
Subtracts the source operand from the destination data register and
sets the condition codes according to the result. The data register
is NOT changed.
FORMAT
-----------------------------------------------------------------
|15 |14 |13 |12 |11 |10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|---|---|---|---|-----------|-----------|-----------|-----------|
| 1 | 0 | 1 | 1 | REGISTER | OP-MODE | MODE | REGISTER |
----------------------------------------=========================
<ea>
OP-MODE
000 8 bits operation.
001 16 bits operation.
010 32 bits operation.
REGISTER
The data register specifies destination Dn.
<ea> specifies source operand, addressing modes allowed are:
--------------------------------- -------------------------------
|Addressing Mode|Mode| Register | |Addressing Mode|Mode|Register|
|-------------------------------| |-----------------------------|
| Dn |000 |N° reg. Dn| | Abs.W |111 | 000 |
|-------------------------------| |-----------------------------|
| An * |001 |N° reg. An| | Abs.L |111 | 001 |
|-------------------------------| |-----------------------------|
| (An) |010 |N° reg. An| | (d16,PC) |111 | 010 |
|-------------------------------| |-----------------------------|
| (An)+ |011 |N° reg. An| | (d8,PC,Xi) |111 | 011 |
|-------------------------------| |-----------------------------|
| -(An) |100 |N° reg. An| | (bd,PC,Xi) |111 | 011 |
|-------------------------------| |-----------------------------|
| (d16,An) |101 |N° reg. An| |([bd,PC,Xi],od)|111 | 011 |
|-------------------------------| |-----------------------------|
| (d8,An,Xi) |110 |N° reg. An| |([bd,PC],Xi,od)|111 | 011 |
|-------------------------------| |-----------------------------|
| (bd,An,Xi) |110 |N° reg. An| | #data |111 | 100 |
|-------------------------------| -------------------------------
|([bd,An,Xi]od) |110 |N° reg. An|
|-------------------------------|
|([bd,An],Xi,od)|110 |N° reg. An|
---------------------------------
* Word and Long only.
RESULT
X - Not affected
N - Set if the result is negative. Cleared otherwise.
Z - Set if the result is zero. Cleared otherwise.
V - Set if an overflow occours. Cleared otherwise.
C - Set if a borrow occours. Cleared otherwise.
SEE ALSO
CMPI CMPA CMPM CMP2
TST CHK CHK2