Motorola DigitalDNA ColdFire MCF5272 User Manual page 460

Data Transfer Mechanism
Table 20-3. Data Bus Byte Strobes (Continued)
Transfer Size
Word
Longword
Line
Table 20-4 lists the bytes that should be driven on the data bus during read cycles by the
external peripheral device being accessed. The entries shown as Byte X are portions of the
requested operand that are read. The operand being read is defined by the size of the transfer
and A[1:0] for the bus cycle. Bytes labeled "X" are don't cares and are not required during
that read cycle. Bytes labeled "–" are not valid transfers.
20-8
Port Size A[1:0]
D[31:24]
8-bit 00
(not
01
supported
for
10
SDRAM)
11
16-bit 00
10
32-bit 00
10
8-bit 00
(not
01
supported
for
10
SDRAM)
11
16-bit 00
10
32-bit 00
8-bit 00
(not
01
supported
for
10
SDRAM)
11
16-bit 00
10
32-bit 00
MCF5272 User's Manual
BS3 BS2
D[23:16] D[15:8]
0 1
0 1
0 1
0 1
0 0
0 0
0 0
1 1
0 1
0 1
0 1
0 1
0 0
0 0
0 0
0 1
0 1
0 1
0 1
0 0
0 0
0 0
BS1 BS0
D[7:0]
1 1
1 1
1 1
1 1
1 1
1 1
1 1
0 0
1 1
1 1
1 1
1 1
1 1
1 1
0 0
1 1
1 1
1 1
1 1
1 1
1 1
0 0