GS4576C09/18/36L
Input Slew Rate Derating
The Address and Command Setup and Hold Derating Values shown in the following table should be added to the default tAS/tCS/
tDS and tAH/tCH/tDH specifications when the slew rate of any of these input signals is less than the 2 V/ns.
To determine the setup and hold time needed for a given slew rate, add the tAS/tCS default specification to the “tAS/tCS VREF to
CK/CK Crossing” and the tAH/tCH default specification to the "tAH/tCH CK/CK Crossing to V " derated values in the Address
REF
and Command Setup and Hold Derating Values table. The derated data setup and hold values can be determined the same way
using the “tDS V
to CK/CK Crossing” and “tDH to CK/CK Crossing to V ” values in the Data Setup and Hold Derating
REF
REF
Values table. The derating values apply to all speed grades.
The setup times in the table relate to a rising signal. The time from the rising signal crossing V
to the CK/CK cross point
IH(AC)MIN
is static and must be maintained across all slew rates. The derated setup timing describes the point at which the rising signal crosses
to the CK/CK cross point. This derated value is calculated by determining the time needed to maintain the given slew
V
REF(DC)
rate and the delta between V
and the CK/CK cross point. All these same values are also valid for falling signals (with
IH(AC)MIN
respect to V
and the CK/ CK cross point).
IL(AC)MAX
The hold times in the table relate to falling signals. The time from the CK/CK cross point to when the signal crosses V
is
IH(DC) MIN
static and must be maintained across all slew rates. The derated hold timing describes the delta between the CK/CK cross point to
when the falling signal crosses V . This derated value is calculated by determining the time needed to maintain the given
REF(DC)
slew rate and the delta between the CK/CK cross point and V
. The hold values are also valid for rising signals (with respect
IH(DC)
to V
and the CK and CK cross point).
IL(DC)MAX
Note: The above descriptions also pertain to data setup and hold derating when CK/CK are replaced with DK/DK.
Rev: 1.04 11/2013
42/62
© 2011, GSI Technology
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
GSI [ GSI TECHNOLOGY ]
