HYS72D64301HBR_07 Datasheet, PDF (17/39 Pages) Qimonda AG – 184-Pin Registered Double-Data-Rate SDRAM Module

Internet Data Sheet
HYS72D[64/128/256]xxxHBR–[5/6]–C
Registered Double-Data-Rate SDRAM Module
7) t_HZ and t_LZ transitions occur in the same access time windows as valid data transitions. These parameters are not referred to a specific
voltage level, but specify when the device is no longer driving (HZ), or begins driving (LZ).
8) Fast slew rate ≥ 1.0 V/ns , slow slew rate ≥ 0.5 V/ns and < 1 V/ns for command/address and CK & CK slew rate > 1.0 V/ns, measured
between V_IH(ac) and V_IL(ac).
9) These parameters guarantee device timing, but they are not necessarily tested on each device.
10) A maximun of eight Autorefresh commands can be posted to any given DDR SDRAM device
11) The specific requirement is that DQS be valid (HIGH,LOW, or some point on a valid transition) on or before this CK edge. A valid transition
is defined as monotonic and meeting the input slew rate specificationsof the device. When no writes were previously in progress on the
bus, DQS will be transitioning from Hi-Z to logic LOW. If a previous write was in progress, DQS could be HIGH, LOW at this time, depending
on t_DQSS.
12) The maximum limit for this parameter is not a device limit. The device operates with a greater value for this parameter, but system
performance (bus turnaround) degrades accordingly.
Rev. 1.22, 2007-08
17
03292006-6N25-8R3I