mcf5307cft90b Freescale Semiconductor, Inc, mcf5307cft90b Datasheet - Page 256

• Manufacturer Part Number: mcf5307cft90b
• Description: Mcf5307 Coldfire Integrated Microprocessor User
• Manufacturer: Freescale Semiconductor, Inc

Synchronous Operation
11.4.3.3 DRAM Controller Mask Registers (DMR0/DMR1)
The DMRn, Figure 11-17, include mask bits for the base address and for address attributes.
They are the same as in asynchronous operation.
Table 11-14 describes DMRn fields.
6
5–4
3
2
1–0
11-22
Reset
Table 11-13. DACR0/DACR1 Field Descriptions (Synchronous Mode) (Continued)
Field
Addr
Bit
R/W
31
Name
IMRS Initiate mode register set (
PM
PS
—
IP
Figure 11-17. DRAM Controller Mask Registers (DMR0 and DMR1)
associated SDRAMs. In initialization, IMRS should be set only after all DRAM controller registers are
initialized and
an SDRAM block programs the SDRAM’s mode register. Thus, the address of the access should be
programmed to place the correct mode information on the SDRAM address pins. Because the
SDRAM does not register this information, it doesn’t matter if the IMRS access is a read or a write or
what, if any, data is put onto the data bus. The DRAM controller clears IMRS after the
finishes.
0 Take no action
1 Initiate
Port size. Indicates the port size of the associated block of SDRAM, which allows for dynamic sizing
of associated SDRAM accesses. PS functions the same in asynchronous operation.
00 32-bit port
01 8-bit port
1x 16-bit port
Initiate precharge all (
finished. Accesses via IP should be no wider than the port size programmed in PS.
0 Take no action.
1 A
Page mode. Indicates how the associated SDRAM block supports page-mode operation.
0 Page mode on bursts only. The DRAM controller dynamically bursts the transfer if it falls within a
1 Continuous page mode. The page stays open and only SCAS needs to be asserted for sequential
Reserved, should be cleared.
executed after all DRAM controller registers are programmed. After IP is set, the next write to an
appropriate SDRAM address generates the
single page and the transfer size exceeds the port size of the SDRAM block. After the burst, the
page closes and a precharge is issued.
SDRAM accesses that hit in the same page, regardless of whether the access is a burst.
PALL
BAM
command is sent to the associated SDRAM block. During initialization, this command is
MRS
Freescale Semiconductor, Inc.
command
PALL
For More Information On This Product,
and
PALL
REFRESH
MBAR + 0x10C (DMR0), 0x114 (DMR1)
MRS
) command. The DRAM controller clears IP after the
Go to: www.freescale.com
MCF5307 User’s Manual
18 17
) command. Setting IMRS generates a
commands have been issued. After IMRS is set, the next access to
Uninitialized
R/W
Description
—
PALL
command to the SDRAM block.
9
WP — C/I AM SC SD UC UD V
8
7
MRS
6
command to the
5
PALL
4
command is
MRS
3
command
2
1
0
0