
Chapter 11. Synchronous/Asynchronous DRAM Controller Module
11-27
Synchronous Operation
11.4.4.2 Interfacing Example
The tables in the previous section can be used to congure the interface in the following
example. To interface one 2M x 32-bit x 4 bank SDRAM component (8 columns) to the
11.4.4.3 Burst Page Mode
SDRAM can efciently provide data when an SDRAM page is opened. As soon as SCAS
is issued, the SDRAM accepts a new address and asserts SCAS every clock for as long as
accesses are in that page. In burst page mode, there are multiple read or write operations for
every ACTV command in the SDRAM if the requested transfer size exceeds the port size of
the associated SDRAM. The primary cycle of the transfer generates the ACTV and READ or
WRITE
commands; secondary cycles generate only READ or WRITE commands. As soon as
the transfer completes, the PALL command is generated to prepare for the next access.
Note that in synchronous operation, burst mode and address incrementing during burst
cycles are controlled by the MCF5307 DRAM controller. Thus, instead of the SDRAM
enabling its internal burst incrementing capability, the MCF5307 controls this function.
This means that the burst function that is enabled in the mode register of SDRAMs must be
disabled when interfacing to the MCF5307.
Figure 11-18 shows a burst read operation. In this example, DACR[CASL] = 01, for an
SRAS-to-SCAS delay (tRCD) of 2 BCLKO cycles. Because tRCD is equal to the read CAS
Table 11-29. MCF5307 to SDRAM Interface (32-Bit Port, 11-Column Address Lines)
MCF5307
Pins
A15 A14 A13 A12 A11 A10
A9
A17 A19 A21 A23 A24 A25 A26 A27 A28 A29 A30 A31
Row
15
14
13
12
11
10
9
171921232425262728293031
Column
2345678
16
18
20
22
SDRAM
Pins
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10 A11 A12 A13 A14 A15 A16 A17 A18
Table 11-30. MCF5307 to SDRAM Interface (32-Bit Port, 12-Column Address Lines)
MCF5307
Pins
A15 A14 A13 A12 A11 A10
A9
A17 A19 A21 A23 A25 A26 A27 A28 A29 A30 A31
Row
15
14
13
12
11
10
9
1719212325262728293031
Column
2345678
16
18
20
22
24
SDRAM
Pins
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10 A11 A12 A13 A14 A15 A16 A17
Table 11-31. SDRAM Hardware Connections
SDRAM
Pins
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10 = CMD
BA0
BA1
MCF5307
Pins
A15
A14
A13
A12
A11
A10
A9
A17
A18
A19
A20
A21
A22
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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