MC68030RC25C Freescale Semiconductor, MC68030RC25C Datasheet - Page 181

• Manufacturer Part Number: MC68030RC25C
• Description: IC MPU 32BIT ENHANCED 128-PGA
• Manufacturer: Freescale Semiconductor

Specifications of MC68030RC25C

• Processor Type: M680x0 32-Bit
• Speed: 25MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 128-PGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -

7
7-20
i
D31
I,
31
the instruction cache, if possible, although the second one is the required
Figure 7-14. Example of Misaligned Cachable Word Transfer from Word Bus
Table 7-6 shows that the processor always prefetches instructions by reading
the processor attempts to fetch the entire 32 bits and loads both words into
word. Even if the instruction access is not cached, the entire 32 bits are latched
a long word from a long-word address (A1 :A0=00), regardless of port size
or alignment. When the required instruction begins at an odd-word boundary,
into an internal cache holding register from which the two instructions words
can subsequently be referenced. Refer to SECTION 11 INSTRUCTION EXE-
CUTION TIMING for a complete description of the cache holding register and
pipeline operation.
031
I
15
OPO
WORD OPERAND (REGISTER) 0
MSB
MSB
Figure 7-15. Misaligned Long-Word Transfer to Long-Word Port
WORD MEMORY
J
DATA BUS
f
OP1
LONG WORD OPERAND
LONG WORD MEMORY
UMB
LSB
DATA BUS
l
D16
I
LMB
0~2
MC68030 USER'S MANUAL
SIZ1
0
1
I
LSB
31
SIZO
0P3
1
O
MC68030
P,
A2
0
DO
0
I
I
0
A1
SIZ1
L
0
1
1
0
AO
SIZO
0P2
O
0
1
MC68030
CACHE ENTRY
1
A2
0
DSACK1 OSACKO
MEMORYCONTROL
1
L
L
A1
1
m m
0
AO
H
1
H
0
OSACK1
MEMORY CONTROL
MOTOROLA
L
L
DSACKO
L
L