EtronTech
EM68916CWQA
NOTE 35: tQH = tHP – tQHS, where: tHP is the minimum of the absolute half period of the actual input clock; and
tQHS is the specification value under the max column. {The less half-pulse width distortion present, the
larger the tQH value is; and the larger the valid data eye will be.}
NOTE 36: When the device is operated with input clock jitter, this parameter needs to be derated by the actual
tERR(6-10per) of the input clock. (output deratings are relative to the SDRAM input clock.)
NOTE 37: When the device is operated with input clock jitter, this parameter needs to be derated by the actual
tJIT(per) of the input clock. (output deratings are relative to the SDRAM input clock.)
NOTE 38: When the device is operated with input clock jitter, this parameter needs to be derated by the actual
tJIT(duty) of the input clock. (output deratings are relative to the SDRAM input clock.)
NOTE 39: When the device is operated with input clock jitter, this parameter needs to be derated by { -
tJIT(duty),max - tERR(6-10per),max } and { - tJIT(duty),min - tERR(6-10per),min } of the actual input clock.
(output deratings are relative to the SDRAM input clock.)
NOTE 40: For tAOFD of DDR2-533, the 1/2 clock of tCK in the 2.5 x tCK assumes a tCH, input clock HIGH pulse
width of 0.5 relative to tCK. tAOF,min and tAOF,max should each be derated by the same amount as the
actual amount of tCH offset present at the DRAM input with respect to 0.5.
NOTE 41: For tAOFD of DDR2-667/800, the 1/2 clock of tCK in the 2.5 x tCK assumes a tCH(avg), average input
clock HIGH pulse width of 0.5 relative to tCK(avg). tAOF,min and tAOF,max should each be derated by the
same amount as the actual amount of tCH(avg) offset present at the DRAM input with respect to 0.5.
Etron Confidential
33
Rev. 1.1
Apr. 2009
ETRON [ ETRON TECHNOLOGY, INC. ]
