AN2491 Freescale Semiconductor / Motorola, AN2491 Datasheet - Page 19

• Manufacturer Part Number: AN2491
• Description: Simplified Mnemonics for PowerPC Instructions
• Manufacturer: Freescale Semiconductor / Motorola

6 Condition Register Logical Simplified Mnemonics
The CR logical instructions, shown in Table 24, can be used to set, clear, copy, or invert a given CR bit.
Simplified mnemonics allow these operations to be coded easily. Note that the symbols defined in Table 8
can be used to identify the CR bit.
Examples using the CR logical mnemonics follow:
7 Trap Instructions Simplified Mnemonics
The codes in Table 25 have been adopted for the most common combinations of trap conditions.
MOTOROLA
1. Set CR[57].
2. Clear CR0[SO].
3. Same as (2), but clear CR3[SO].
4. Invert the CR0[EQ].
5. Same as (4), but CR4[EQ] is inverted and the result is placed into CR5[EQ].
Code
eq
ge
ne
ng
lle
le
gt
nl
llt
lt
crset 25
crclr so
crclr 4 * cr3 + so
crnot eq,eq
crnot 4 * cr5 + eq,4 * cr4 + eq
Less than
Less than or equal
Equal
Greater than or equal
Greater than
Not less than
Not equal
Not greater than
Logically less than
Logically less than or equal
Condition register set
Condition register clear
Condition register move
Condition register not
Table 24. Condition Register Logical Simplified Mnemonics
Operation
Description
Simplified Mnemonics for PowerPC™ Instructions
Freescale Semiconductor, Inc.
Table 25. Standard Codes for Trap Instructions
For More Information On This Product,
Go to: www.freescale.com
equivalent to
equivalent to
equivalent to
equivalent to
equivalent to
Simplified Mnemonic
crmove bx,by
TO Encoding
crnot bx,by
crset bx
crclr bx
16
20
12
12
24
20
Condition Register Logical Simplified Mnemonics
4
8
2
6
<
1
1
0
0
0
0
1
1
0
0
creqv bx,bx,bx
crxor bx,bx,bx
crnor bx,by,by
Equivalent to
cror bx,by,by
creqv 25,25,25
crxor 3,3,3
crxor 15,15,15
crnor 2,2,2
crnor 22,18,18
>
0
0
0
1
1
1
1
0
0
0
=
0
1
1
1
0
1
0
1
0
1
<U
0
0
0
0
0
0
0
0
1
1
1
>U
0
0
0
0
0
0
0
0
0
0
2
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