Data Sheet 20 Rev. 1.1, 2004-05
HYS64D64020[H/G]BDL–[5/6]–C
Small Outline DDR SDRAM Modules
Electrical Characteristics
Read preamble tRPRE 0.9 1.1 0.9 1.1 tCK 2)3)4)5)
Read postamble tRPST 0.40 0.60 0.40 0.60 tCK 2)3)4)5)
Active to Precharge command tRAS 40 70E+3 42 70E+3 ns 2)3)4)5)
Active to Active/Auto-refresh command period tRC 55 — 60 — ns 2)3)4)5)
Auto-refresh to Active/Auto-refresh command
period tRFC 70 — 72 — ns 2)3)4)5)
Active to Read or Write delay tRCD 15 — 18 — ns 2)3)4)5)
Precharge command period tRP 15 — 18 — ns 2)3)4)5)
Active to Autoprecharge delay tRAP tRCD or tRASmin ns 2)3)4)5)
Active bank A to Active bank B command tRRD 10 — 12 — ns 2)3)4)5)
Write recovery time tWR 15 — 15 — ns 2)3)4)5)
Auto precharge write recovery + precharge
time tDAL (tWR/tCK)+(tRP/tCK)tCK 2)3)4)5)11)
Internal write to read command delay tWTR 2—1—tCK 2)3)4)5)
Exit self-refresh to non-read command tXSNR 75 — 75 — ns 2)3)4)5)
Exit self-refresh to read command tXSRD 200 — 200 — tCK 2)3)4)5)
Average Periodic Refresh Interval tREFI — 7.8 — 7.8 µs2)3)4)5)12)
1) 0 °C ≤ TA ≤ 70 °C; VDDQ = 2.5 V ± 0.2 V, VDD = +2. 5 V ± 0.2 V (DDR333); VDDQ = 2.6 V ± 0.1 V, VDD = +2.6 V ±0.1 V
(DDR400)
2) Input slew rate ≥ 1 V/ns for DDR400, DDR333
3) The CK/CK inpu t reference lev el (for timin g reference to C K/CK) i s the point at w hich CK and CK cross: the in put referenc e
level for signals other than CK/CK, is VREF. CK/CK slew rate are ≥ 1.0 V/ns.
4) Inputs are not recognized as valid until VREF stabilizes.
5) The Output timing reference le vel, as measured at the timing reference point indicated in AC Characteri stics (note 3) is VTT.
6) These parameters guarantee device timing, but they are not necessarily tested on each device.
7) tHZ and tLZ trans itions oc cur in the same acc ess time win dows as valid dat a transit ions. These para meters are not referred
to a specific voltage level, but specify when the device is no longer driving (HZ), or begins driving (LZ).
8) The specific req ui rem ent is th at D Q S b e v al id (HIG H, LOW, or so me po int on a va lid transitio n) on or b efo re this CK edge.
A valid tran sition is defin ed as monoton ic and meeting the input slew rate specifi cations of t he device. Whe n 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, or transitioning from HIGH to LOW at this time, depending on tDQSS.
9) The maximu m limi t for this parameter is not a dev ice lim it. The d evice operate s with a greater valu e for th is parame ter, bu t
system performance (bus turnaround) degrades accordingly.
10) F as t sl ew ra te ≥ 1.0 V /ns , sl o w sl ew ra t e ≥ 0.5 V/ns and < 1 V/ns for command/address and CK & CK slew rate > 1.0 V/
ns, measured between VIH(ac) and VIL(ac).
11) For each of the terms, if not already an integer, round to the next highest integer. tCK is equal to the actual system clock
cycle time.
12) A maximum of eight Autorefresh commands can be posted to any given DDR SDRAM device.
Table 13 AC Timing - Absolute Specifications for PC3200 and PC2700
Parameter Symbol –5 –6 Unit Note/ Test
Condition 1)
DDR400B DDR333
Min. Max. Min. Max.