MC68EC020FG25 Freescale Semiconductor, MC68EC020FG25 Datasheet - Page 67
MC68EC020FG25
Manufacturer Part Number
MC68EC020FG25
Description
IC MPU 32 BIT 25MHZ 100-QFP
Manufacturer
Freescale Semiconductor
Datasheet
1.MC68EC020AA16.pdf
(306 pages)
Specifications of MC68EC020FG25
Processor Type
M680x0 32-Bit
Speed
25MHz
Voltage
5V
Mounting Type
Surface Mount
Package / Case
100-QFP
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Features
-
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
MC68EC020FG25
Manufacturer:
FREESCALE
Quantity:
8 831
Company:
Part Number:
MC68EC020FG25
Manufacturer:
Freescale Semiconductor
Quantity:
10 000
Part Number:
MC68EC020FG25
Manufacturer:
MOTOROL
Quantity:
20 000
- Current page: 67 of 306
- Download datasheet (2Mb)
5.2.3 Effects of Dynamic Bus Sizing and Operand Misalignment
The combination of operand size, operand alignment, and port size determine the number
of bus cycles required to perform a particular memory access. Table 5-6 lists the number
of bus cycles required for different operand sizes to different port sizes with all possible
alignment conditions for read/write cycles.
Table 5-6 reveals that bus cycle throughput is significantly affected by port size and
alignment. The MC68020/EC020 system designer and programmer should be aware of
and account for these effects, particularly in time-critical applications.
5-20
31
D31
OP0
MSB
OP1
XXX
*
Instruction prefetches are always two words from a long-word boundary
Instruction
Byte Operand
Word Operand
Long-Word Operand
Figure 5-17. Misaligned Long-Word Operand Read
LONG-WORD OPERAND (REGISTER)
Operand Size
OP1
UMB
OP2
Table 5-6. Memory Alignment and Port Size
XXX
LONG-WORD MEMORY
*
Influence on Read/Write Bus Cycles
DATA BUS
from Long-Word Port Example
M68020 USER’S MANUAL
LMB
XXX
OP3
OP2
1:2:4
1:1:2
1:2:4
1:1:1
(Data Port Size = 32 Bits:16 Bits:8 Bits)
00
Number of Bus Cycles
OP0
LSB
XXX
OP3
1:1:1
1:2:2
2:3:4
N/A
01
A1, A0
D0
0
SIZ1 SIZ0 A2
0
1
1:1:1
1:1:2
2:2:4
N/A
10
MC68020/EC020
0
1
0
1
A1
1:1:1
2:2:2
2:3:4
1
0
N/A
11
A0
1
0
MEMORY CONTROL
DSACK1
L
L
MOTOROLA
DSACK0
L
L
Related parts for MC68EC020FG25
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
Manufacturer:
Freescale Semiconductor, Inc
Datasheet:
Part Number:
Description:
Manufacturer:
Freescale Semiconductor, Inc
Datasheet:
Part Number:
Description:
Manufacturer:
Freescale Semiconductor, Inc
Datasheet:
Part Number:
Description:
Manufacturer:
Freescale Semiconductor, Inc
Datasheet:
Part Number:
Description:
Manufacturer:
Freescale Semiconductor, Inc
Datasheet:
Part Number:
Description:
Manufacturer:
Freescale Semiconductor, Inc
Datasheet:
Part Number:
Description:
Manufacturer:
Freescale Semiconductor, Inc
Datasheet:
Part Number:
Description:
Manufacturer:
Freescale Semiconductor, Inc
Datasheet:
Part Number:
Description:
Manufacturer:
Freescale Semiconductor, Inc
Datasheet:
Part Number:
Description:
Manufacturer:
Freescale Semiconductor, Inc
Datasheet:
Part Number:
Description:
Manufacturer:
Freescale Semiconductor, Inc
Datasheet:
Part Number:
Description:
Manufacturer:
Freescale Semiconductor, Inc
Datasheet:
Part Number:
Description:
Manufacturer:
Freescale Semiconductor, Inc
Datasheet:
Part Number:
Description:
Manufacturer:
Freescale Semiconductor, Inc
Datasheet:
Part Number:
Description:
Manufacturer:
Freescale Semiconductor, Inc
Datasheet: