HYMD525G726AS4-M Datasheet, PDF (12/17 Pages) Hynix Semiconductor – Registered DDR SDRAM DIMM

HYMD525G726A(L)S4M-M/K/H/L
11.This derating table is used to increase tDS/tDH in case where the input slew-rate is below 0.5V/ns.
Input Setup / Hold Slew-rate Derating Table.
Input Setup / Hold Slew-rate
Delta tDS
Delta tDH
V/ns
ps
ps
0.5
0
0
0.4
+75
+75
0.3
+150
+150
12. I/O Setup/Hold Plateau Derating. This derating table is used to increase tDS/tDH in case where the input level is flat below VREF
+/-310mV for a duration of up to 2ns.
I/O Input Level
Delta tDS
Delta tDH
mV
ps
ps
+280
+50
+50
13. I/O Setup/Hold Delta Inverse Slew Rate Derating. This derating table is used to increase tDS/tDH in case where the DQ and DQS
slew rates differ. The Delta Inverse Slew Rate is calculated as (1/SlewRate1)-(1/SlewRate2). For example, if slew rate 1 = 0.5V/ns
and Slew Rate2 = 0.4V/n then the Delta Inverse Slew Rate = -0.5ns/V.
(1/SlewRate1)-(1/SlewRate2)
Delta tDS
Delta tDH
ns/V
ps
ps
0
0
0
+/-0.25
+50
+50
+/- 0.5
+100
+100
14. DQS, DM and DQ input slew rate is specified to prevent double clocking of data and preserve setup and hold times. Signal transi
tions through the DC region must be monotonic.
15. tDAL = (tDPL / tCK ) + (tRP / tCK ). For each of the terms above, if not already an integer, round to the next highest integer. tCK
is equal to the actual system clock cycle time.
Example: For DDR266B at CL=2.5 and tCK = 7.5 ns,
tDAL = (15 ns / 7.5 ns) + (20 ns / 7.5 ns) = (2.00) + (2.67)
Round up each non-integer to the next highest integer: = (2) + (3), tDAL = 5 clock
16. For the parts which do not has internal RAS lockout circuit, Active to Read with Auto precharge delay should be
tRAS - BL/2 x tCK.
Rev. 0.3 / Apr. 2004
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