CoMPare register against upper and lower bounds
NAME
Cmp2 -- Compare register against upper and lower bounds (68020+)
SYNOPSIS
CMP2 <ea>,Rn
FUNCTION
Used to compare value of Rn (Dn or An) with two lower and upper
bounds, which are stored in memory, at address given by <ea> (in
two adjacent areas).
Lower bound have to be stored before upper bound. Flags are set
following to the result of comparison.
If Rn is a data register Dn, and if operation is made on 8 or
16 bits, only the 8 or 16 bits of Dn are taken in count.
In opposite, in the case of Rn as an address register and if a 16
bits operation is granted, the 32 bits of An are compared to bounds
which are, them, extended on 32 bits by their signs.
FORMAT
<ea>
----------------------------------------=========================
|15 |14 |13 |12 |11 |10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|---|---|---|---|---|-------|---|---|---|-----------|-----------|
| 0 | 0 | 0 | 0 | 0 | SIZE | 0 | 1 | 1 | MODE | REGISTER |
|---|-----------|---|-------|---|---|---|-----------|-----------|
|D/A| REGISTER | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
-----------------------------------------------------------------
REGISTER
Register specifies the register Rn which contains the value to test.
If D/A = 0: Rn = Dn
If D/A = 1: Rn = An
<ea> specifies bounds, addressing modes allowed are:
--------------------------------- -------------------------------
|Addressing Mode|Mode| Register | |Addressing Mode|Mode|Register|
|-------------------------------| |-----------------------------|
| Dn | - | - | | Abs.W |111 | 000 |
|-------------------------------| |-----------------------------|
| An | - | - | | Abs.L |111 | 001 |
|-------------------------------| |-----------------------------|
| (An) |010 |N° reg. An| | (d16,PC) |111 | 010 |
|-------------------------------| |-----------------------------|
| (An)+ | - | - | | (d8,PC,Xi) |111 | 011 |
|-------------------------------| |-----------------------------|
| -(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 | - | - |
|-------------------------------| -------------------------------
|([bd,An,Xi]od) |110 |N° reg. An|
|-------------------------------|
|([bd,An],Xi,od)|110 |N° reg. An|
---------------------------------
SIZE
00->one Byte operation
01->one Word operation
10->one Long operation
RESULT
X - Not affected
N - Undefined.
Z - Set if Rn is equal to one of the two bounds. Cleared otherwise.
V - Undefined.
C - Set if Rn is out of bounds. Cleared otherwise.
SEE ALSO
CMP CMPI CMPA
CHK2
HTML Conversion by AG2HTML.pl V2.941126c, perl $RCSfile: cmp2.HTML,v $$Revision: 1.1 $$Date: 1999/09/14 21:14:08 $
Patch level: 36
& witbrock@cs.cmu.edu