mpc8568e Freescale Semiconductor, Inc, mpc8568e Datasheet - Page 21

• Manufacturer Part Number: mpc8568e
• Description: Mpc8568e Powerquicc Iii Processor
• Manufacturer: Freescale Semiconductor, Inc

6.2
This section provides the AC electrical characteristics for the DDR SDRAM interface.
6.2.1
Table 17
Table 18
Table 19
Freescale Semiconductor
At recommended operating conditions
At recommended operating conditions.
At recommended operating conditions.
AC input low voltage
AC input high voltage
AC input low voltage
AC input high voltage
Controller Skew for
MDQS—MDQ/MECC/MDM
Note:
1. t
2. The amount of skew that can be tolerated from MDQS to a corresponding MDQ signal is called t
3. Maximum DDR1 frequency is 400 MHz.
bit that will be captured with MDQS[n]. This should be subtracted from the total timing budget.
determined by the following equation: t
is the absolute value of t
CISKEW
provides the input AC timing specifications for the DDR2 SDRAM when
provides the input AC timing specifications for the DDR SDRAM when GV
provides the input AC timing specifications for the DDR SDRAM interface.
DDR SDRAM AC Electrical Characteristics
MPC8568E/MPC8567E PowerQUICC III™ Integrated Processor Hardware Specifications, Rev. 0
DDR SDRAM Input AC Timing Specifications
represents the total amount of skew consumed by the controller between MDQS[n] and any corresponding
Parameter
Parameter
Parameter
Table 17. DDR2 SDRAM Input AC Timing Specifications for 1.8-V Interface
Table 18. DDR SDRAM Input AC Timing Specifications for 2.5-V Interface
Table 19. DDR SDRAM Input AC Timing Specifications
CISKEW
533 MHz
400 MHz
333 MHz
.
DISKEW
Symbol
Symbol
Symbol
t
CISKEW
V
V
V
V
IH
IH
IL
IL
=+/-(T/4 – abs(t
MV
MV
REF
REF
–300
–365
–390
Min
Min
Min
—
—
CISKEW
+ 0.25
+ 0.31
)) where T is the clock period and abs(t
MV
MV
REF
REF
Max
Max
Max
300
365
390
—
—
– 0.25
– 0.31
GV
DISKEW
DD
Unit
Unit
Unit
DDR and DDR2 SDRAM
DD
ps
V
V
V
V
(typ)=2.5 V.
(typ)=
.This can be
CISKEW
1.8 V.
Notes
Notes
Notes
1, 2
—
—
—
—
—
—
3
)
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