Word Operand Write To Byte Port Example - Motorola MC68020 User Manual

Figure 5-7 shows a word write to an 8-bit bus port. Like the preceding example, this
example requires two bus cycles. Each bus cycle transfers a single byte. SIZ1 and SIZ0
for the first cycle specify two bytes; for the second cycle, one byte. Figure 5-8 shows the
associated bus transfer signal timing.
Figure 5-7. Word Operand Write to Byte Port Example
5-12
WORD OPERAND
15
OP2 OP3
D31 DATA BUS D24
BYTE MEMORY MC68020/EC020
SIZ1 SIZ0 A1
OP2 1
OP3
0
M68020 USER'S MANUAL
0
MEMORY CONTROL
A0 DSACK1
0 0 0 H
1 0 1 H
DSACK0
L
L
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