mcf5282 Freescale Semiconductor, Inc, mcf5282 Datasheet - Page 281

• Manufacturer Part Number: mcf5282
• Manufacturer: Freescale Semiconductor, Inc

15.2.3
To reduce system logic and to support a variety of SDRAM sizes, the DRAM controller provides SDRAM
control signals as well as a multiplexed row address and column address to the SDRAM.
15.2.3.1 Address Multiplexing
Table 15-7
address connection configurations can be derived from this table.
The following tables provide a more comprehensive, step-by-step way to determine the correct address
line connections for interfacing the ColdFire processor to the SDRAM. To use the tables, find the one that
corresponds to the number of column address lines on the SDRAM and to the port size as seen by the
processor, which is not necessarily the SDRAM port size. For example, if two 1M x 16-bit SDRAMs
together form a 1M x 32-bit memory, the port size is 32 bits. Most SDRAMs likely have fewer address
lines than are shown in the tables, so follow only the connections shown until all SDRAM address lines
are connected.
Freescale Semiconductor
Address Pin
17
16
15
14
13
12
11
10
17
18
19
20
21
22
23
9
General Synchronous Operation Guidelines
shows the generic address multiplexing scheme for SDRAM configurations. All possible
Because the processor has 24 extermal address lines, the maximum
SDRAM address size is 128 Mbits.
Row Address
17
16
15
14
13
12
11
10
17
18
19
20
21
22
23
9
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3
Table 15-7. Generic Address Multiplexing Scheme
Column Address
16
17
18
19
20
21
22
0
1
2
3
4
5
6
7
8
8-bit port only
8- and 16-bit ports only
32-bit port only
16-bit port only or 32-bit port with only 8 column address lines
16-bit port only when at least 9 column address lines are used
NOTE
Notes Relating to Port Sizes
Synchronous DRAM Controller Module
15-9