MPC555CME Freescale Semiconductor, MPC555CME Datasheet - Page 183

• Manufacturer Part Number: MPC555CME
• Description: KIT EVALUATION FOR MPC555
• Manufacturer: Freescale Semiconductor
• Type: Microcontrollerr

Specifications of MPC555CME

• Contents: Module Board, Installation Guide, Power Supply, Cable, Software and more
• Processor To Be Evaluated: MPC555
• Data Bus Width: 32 bit
• Interface Type: RS-232
• For Use With/related Products: MPC555
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

MPC555
USER’S MANUAL
n+1
(n) and (n+1) are word addresses in the original uncompressed code
n
n+1
n
The compiler will set the left and right stream boundary at either bit 12 or bit 19. This
will be determined by the most efficient placement of compressed instruction code.
The boundary will be placed between bits 11 and 12 if bit 31 is equal to one. The
boundary will be placed between bits 18 and 19 if bit 31 is equal to zero. The original
right and left streams may span an adjacent base addresses before or after each oth-
er. This fact will also determine the placement of the boundary bit field.
Each stream line may include a variable number of compressed symbols, depending
on how well the bytes in the original stream were compressed.
The decompressor has to maintain two bit pointers (left and right) in order to have ac-
cess to the start location of any instruction’s half.
The decompressor maintains tracking of the base address, to start fetching from the
next address in the memory.
Xn,1
/
Uncompressed Code
0
0
MPC556
Figure 4-6 Examples of Compressed Symbols Layout
Xn,2
8
8
Xn+1,1
Rev. 15 October 2000
BURST BUFFER
Boundary assumed to be 12 for both lines
15
15
Compressed Code Stream
0
0
MOTOROLA
11
11
4-7