Mc68030 Internal To External Data Bus Multiplexer - Write Cycles - Motorola MC68030 User Manual

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Table 7-5. MC68030 Internal to External Data Bus
Multiplexer - Write Cycles
Transfer
Size Address External Oata Bus Connection
Size
SIZ1 SIZO
A1
AO 031 :024 023:016 015:08 07:00
Byte 0
1 x x
OP3 OP3 OP3 OP3
Word
1 0 x
0 OP2 OP3 OP2 OP3
1
0
x 1 OP2
OP2 OP3
OP2
3 Byte 1 1
0 0 OP1 OP2 OP3 OPO*
1 1
0
1
OP1 OP1 OP2 OP3
1 1 1
0
I
OP1
OP2 OP1 OP2
1 1 1 1
I
OP1 OP1 OP2* OP1
Long Word 0 0 0 9
I
OPO OP1 OP2 OP3
0 0 0
1
I
OPO OPO OP1 OP2
0 0
1
0
I
OPO OP1 OPO OP1
0 0 1 1
I
OPO OPO OP1* OPO
*Oue to the current implementation, this byte is output but never used.
x = don't care
NOTE: The OP tables on the external data bus refer to a particular byte of the operand
that is written on that section of the data bus.
31
LONG WORD OPERAND
OPO
I
OPI OP2
031
DATA BUS
016
+
WORD MEMORY
MSB LSB
OPO OPI
OP2 OP3
OP3
MC68030
SIZI SIZO A I AO
0 0 0
MEMORY CONTROL
DSACKI DSACKO
H
Figure 7-5. Example of Long-Word Transfer to Word Port
MC68030 USER'S MANUAL
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