DDR SDRAM 256Mb E-die (x4, x8)
DDR SDRAM
Overshoot/Undershoot specification for Data, Strobe, and Mask Pins
Specification
DDR400
1.2V
Parameter
Maximum peak amplitude allowed for overshoot
Maximum peak amplitude allowed for undershoot
1.2V
The area between the overshoot signal and VDD must be less than or equal to
The area between the undershoot signal and GND must be less than or equal to
2.5V-ns
2.5V-ns
VDDQ
Overshoot
5
Maximum Amplitude = 1.2V
4
3
2
Area = 2.4V-ns
1
0
-1
-2
Maximum Amplitude = 1.2V
GND
-3
-4
-5
0
0.5 1.0 1.42 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 5.68 6.0 6.5 7.0
Tims(ns)
undershoot
DQ/DM/DQS AC overshoot/Undershoot Definition
Rev. 1.1 September. 2003