MCF5480 Freescale Semiconductor, Inc, MCF5480 Datasheet - Page 18

• Manufacturer Part Number: MCF5480
• Description: Mcf548x Coldfire Microprocessor
• Manufacturer: Freescale Semiconductor, Inc

SDRAM Bus
9.2
When using the DDR SDRAM controller, the following timing numbers must be followed to properly latch or drive data onto
the memory bus. All timing numbers are relative to the four DQS byte lanes.
Table
18
Symbol
DD10
DD11
DD12
DD1
DD2
DD3
DD4
DD5
DD6
DD7
DD8
DD9
12shows the DDR clock crossover specifications.
1
Symbol
The clock crossover voltage is only guaranteed when using the highest drive strength option for the SDCLK[1:0]
and SDCLK[1:0] signals.
V
V
V
V
OUT
MP
DDR SDRAM AC Timing Characteristics
Frequency of Operation
Clock Period (t
Pulse Width High (t
Pulse Width Low (t
Address, SDCKE, CAS, RAS, WE, SDBA, SDCS—Output
Valid (t
Address, SDCKE, CAS, RAS, WE, SDBA, SDCS—Output Hold
(t
Write Command to first DQS Latching Transition (t
Data and Data Mask Output Setup (DQ−>DQS) Relative to
DQS (DDR Write Mode) (t
Data and Data Mask Output Hold (DQS−>DQ) Relative to DQS
(DDR Write Mode) (t
Input Data Skew Relative to DQS (Input Setup) (t
Input Data Hold Relative to DQS (t
DQS falling edge to SDCLK rising (output setup time) (t
DQS falling edge from SDCLK rising (output hold time) (t
ID
IX
SDCLK
SDCLK
CMH
)
Clock output mid-point voltage
Clock output voltage level
Clock output differential voltage (peak to peak swing)
Clock crossing point voltage
CMV
)
CK
)
CKL
CKH
QH
)
)
)
Characteristic
Table 12. DDR Clock Crossover Specifications
QS
Characteristic
MCF548x ColdFire
Figure 15. DDR Clock Timing Diagram
)
Table 13. DDR Timing Specifications
1
IH
)
®
IS
Microprocessor, Rev. 4
DQSS
)
)
DSS
DSH
)
)
0.25 × SDCLK
+ 0.5ns
7.52
0.45
0.45
Min
50
2.0
1.0
1.0
0.5
0.5
—
—
1.05
–0.3
1.05
Min
0.7
1
0.5 × SDCLK
SD_VDD + 0.3
SD_VDD + 0.6
+ 1.0 ns
Max
0.55
0.55
1.25
133
12
—
—
—
—
—
—
1
Max
1.45
1.45
V
V
V
Freescale Semiconductor
IX
MP
IX
V
SDCLK
SDCLK
SDCLK
ID
MHz
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
Unit
V
V
V
V
Notes
10
11
2
3
4
5
6
7
8
9