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MCF5329 ColdFire
Microprocessor Data Sheet, Rev. 0.1
Preliminary
Preliminary Electrical Characteristics
Freescale Semiconductor
28
5.8.2
DDR SDRAM AC Timing Characteristics
When using the SDRAM controller in DDR mode, 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. The following timing numbers are subject to change at anytime, and are only provided to aid in early
board design. Please contact your local Freescale representative if questions develop.
Table 12. DDR Timing Specifications
Num
Characteristic
Symbol
Min
Max
Unit
Notes
Frequency of Operation
t
DDCK
80
TBD
Mhz
1
NOTES:
1
The frequency of operation is either 2x or 4x the FB_CLK frequency of operation. FlexBus and SDRAM clock operate at the
same frequency as the internal bus clock.
2
SD_CLK is one SDRAM clock in (ns).
3
Pulse width high plus pulse width low cannot exceed min and max clock period.
4
Command output valid should be 1/2 the memory bus clock (SD_CLK) plus some minor adjustments for process,
temperature, and voltage variations.
5
This specification relates to the required input setup time of today’s DDR memories. Rigoletto’s output setup should be larger
than the input setup of the DDR memories. If it is not larger, then the input setup on the memory will be in violation.
MEM_DATA[31:24] is relative to MEM_DQS[3], MEM_DATA[23:16] is relative to MEM_DQS[2], MEM_DATA[15:8] is relative to
MEM_DQS[1], and MEM_[7:0] is relative MEM_DQS[0].
6
The first data beat will be valid before the first rising edge of DQS and after the DQS write preamble. The remaining data
beats will be valid for each subsequent DQS edge.
7
This specification relates to the required hold time of today’s DDR memories. MEM_DATA[31:24] is relative to MEM_DQS[3],
MEM_DATA[23:16] is relative to MEM_DQS[2], MEM_DATA[15:8] is relative to MEM_DQS[1], and MEM_[7:0] is relative
MEM_DQS[0].
DD1
Clock Period
t
DDSK
TBD
12.5
ns
2
DD2
Pulse Width High
t
DDCKH
0.45
0.55
SD_CLK
3
DD3
Pulse Width Low
t
DDCKL
0.45
0.55
SD_CLK
3
DD4
Address, SD_CKE, SD_CAS, SD_RAS, SD_WE,
SD_CS[1:0] - Output Valid
t
SDCHACV
—
0.5
×
SD_CLK
+ 1.0
ns
4
DD5
Address, SD_CKE, SD_CAS, SD_RAS, SD_WE,
SD_CS[1:0] - Output Hold
t
SDCHACI
2.0
—
ns
DD6
Write Command to first DQS Latching Transition
t
CMDVDQ
—
1.25
SD_CLK
DD7
Data and Data Mask Output Setup (DQ-->DQS)
Relative to DQS (DDR Write Mode)
t
DQDMV
1.5
—
ns
5
6
DD8
Data and Data Mask Output Hold (DQS-->DQ)
Relative to DQS (DDR Write Mode)
t
DQDMI
1.0
—
ns
7
DD9
Input Data Skew Relative to DQS (Input Setup)
t
DVDQ
—
1
ns
8
DD10 Input Data Hold Relative to DQS.
t
DIDQ
0.25
×
SD_CLK
+ 0.5ns
—
ns
9
DD11 DQS falling edge from SDCLK rising (output hold time) t
DQLSDCH
0.5
—
ns
DD12 DQS input read preamble width
t
DQRPRE
0.9
1.1
SD_CLK
DD13 DQS input read postamble width
t
DQRPST
0.4
0.6
SD_CLK
DD14 DQS output write preamble width
t
DQWPRE
0.25
SD_CLK
DD15 DQS output write postamble width
t
DQWPST
0.4
0.6
SD_CLK