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MSC8144EC Datasheet, PDF (39/80 Pages) Freescale Semiconductor, Inc – Quad Core Digital Signal Processor
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Electrical Characteristics
Table 25. DDR SDRAM Input AC Timing Specifications for 2.5-V Interface (continued)
Parameter
AC input high voltage
Note: At recommended operating conditions with VDDDDR of 2.5 ± 5%.
Symbol
VIH
Min
MVREF + 0.31
Max
Unit
—
V
Table 26 provides the input AC timing specifications for the DDR SDRAM when VDDDDR (typ) = 1.8 V.
Table 26. DDR2 SDRAM Input AC Timing Specifications for 1.8-V Interface
Parameter
AC input low voltage
AC input high voltage
Note: At recommended operating conditions with VDDDDR of 1.8 ± 5%.
Symbol
VIL
VIH
Min
—
MVREF + 0.25
Max
MVREF – 0.25
—
Unit
V
V
Table 27 provides the input AC timing specifications for the DDR SDRAM interface.
Table 27. DDR SDRAM Input AC Timing Specifications
Parameter
Symbol
Min
Max
Unit
Controller Skew for MDQS—MDQ/MECC/MDM1
• 400 MHz
• 333 MHz
• 266 MHz
• 200 MHz
tCISKEW
–365
–390
–428
–490
365
ps
390
ps
428
ps
490
ps
Notes: 1. tCISKEW represents the total amount of skew consumed by the controller between MDQS[n] and any corresponding bit that is
captured with MDQS[n]. Subtract this value from the total timing budget.
2. At recommended operating conditions with VDDDDR (1.8 V or 2.5 V) ± 5%
2.7.4.2 DDR SDRAM Output AC Timing Specifications
Table 28 provides the output AC timing specifications for the DDR SDRAM interface.
Table 28. DDR SDRAM Output AC Timing Specifications
Parameter
MCK[n] cycle time, (MCK[n]/MCK[n] crossing)2
ADDR/CMD output setup with respect to MCK3
• 400 MHz
• 333 MHz
• 266 MHz
• 200 MHz
ADDR/CMD output hold with respect to MCK3
• 400 MHz
• 333 MHz
• 266 MHz
• 200 MHz
MCSn output setup with respect to MCK3
• 400 MHz
• 333 MHz
• 266 MHz
• 200 MHz
MCSn output hold with respect to MCK3
• 400 MHz
• 333 MHz
• 266 MHz
• 200 MHz
MCK to MDQS Skew4
Symbol 1
tMCK
tDDKHAS
tDDKHAX
tDDKHCS
tDDKHCX
tDDKHMH
Min
3
1.95
2.40
3.15
4.20
1.95
2.40
3.15
4.20
1.95
2.40
3.15
4.20
1.95
2.40
3.15
4.20
–0.6
Max
10
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
0.6
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
MSC8144EC Quad Core Digital Signal Processor Data Sheet, Rev. 6
Freescale Semiconductor
39
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