MPC555
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MPC556
BURST BUFFER
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
4-9
:
Figure 4-8 Examples of Instruction Layout in Memory
4.3.6 Compressed Address Format – Direct Branches
The one pointer format is used for the conditional and unconditional direct branches.
illustrates the one pointer format. The word pointer for the unconditional
branch has nineteen bits (the lower two-byte bits are ignored). This will yield an uncon-
ditional branch displacement limit of two Mbytes. The word pointer for the conditional
0 1
Compressed
Instruction
Base Address
x
x+4
0
19
Word Pointer - Base Address
22
26 27
31
Right
Pointer
Pointer
Left
Left/Right = X (don’t care) ( Left and Right are at the base address), Same_Line = 0
Base Address
x
x+4
1 1
X 0
0
19
Word Pointer - Base Address
22
26 27
31
Right
Pointer
Pointer
Left
0
19
Word Pointer - Base Address
22
26 27
31
Right
Pointer
Pointer
Left
Left/Right = 1 (Right side is first at the base address), Same_Line = 1
Left/Right = 0 (Left side is first at the base address), Same_Line = 1
Base Address
x
x+4
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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