Rev. 1.11 - UBiio

Internet Data Sheet
HY[B/I]18T256[40/80/16]0B[C/F](L)
256-Mbit Double-Data-Rate-Two SDRAM
34) For these parameters, the DDR2 SDRAM device is characterized and verified to support t nPARAM = RU{t PARAM / t CK.AVG }, which is in clock
cycles, assuming all input clock jitter specifications are satisfied. For example, the device will support t nRP = RU{t RP / t CK.AVG }, which is in
clock cycles, if all input clock jitter specifications are met. This means: For DDR2–667 5–5–5, of which t RP = 15 ns, the device will support
t nRP = RU{t RP / t CK.AVG } = 5, i.e. as long as the input clock jitter specifications are met, Precharge command at Tm and Active command at
Tm + 5 is valid even if (Tm + 5 - Tm) is less than 15 ns due to input clock jitter.
35) t WTR is at lease two clocks (2 x t CK ) independent of operation frequency.
TABLE 53
DRAM Component Timing Parameter by Speed Grade - DDR2–667
Parameter Symbol DDR2–667 Unit Notes 1)2)3)4)5)6)
DQ output access time from CK / CK t AC –450 +450 ps
CAS to CAS command delay t CCD 2 — nCK
Average clock high pulse width t CH.AVG 0.48 0.52 t CK.AVG
9)10)
Average clock period t CK.AVG 3000 8000 ps
CKE minimum pulse width ( high and low pulse t CKE 3 — nCK
11)
width)
Average clock low pulse width t CL.AVG 0.48 0.52 t CK.AVG
9)10)
Auto-Precharge write recovery + precharge time t DAL WR + t nRP — nCK
12)13)
Minimum time clocks remain ON after CKE
asynchronously drops LOW
Min.
Max.
t DELAY t IS + t CK .AVG +
t IH
–– ns
DQ and DM input hold time t DH.BASE 175 –– ps
7)
8)
18)19)14)
DQ and DM input pulse width for each input t DIPW 0.35 — t CK.AVG
DQS output access time from CK / CK t DQSCK –400 +400 ps
8)
DQS input high pulse width t DQSH 0.35 — t CK.AVG
DQS input low pulse width t DQSL 0.35 — t CK.AVG
DQS-DQ skew for DQS & associated DQ signals t DQSQ — 240 ps
15)
DQS latching rising transition to associated clock
edges
t DQSS – 0.25 + 0.25 t CK.AVG
16)
DQ and DM input setup time t DS.BASE 100 –– ps
17)18)19)
DQS falling edge hold time from CK t DSH 0.2 — t CK.AVG
16)
DQS falling edge to CK setup time t DSS 0.2 — t CK.AVG
16)
CK half pulse width t HP Min(t CH.ABS ,
t CL.ABS )
__ ps
20)
Data-out high-impedance time from CK / CK t HZ — t AC.MAX ps
Address and control input hold time t IH.BASE 275 — ps
24)22)
Control & address input pulse width for each input t IPW 0.6 — t CK.AVG
Address and control input setup time t IS.BASE 200 — ps
DQ low impedance time from CK/CK t LZ.DQ 2xt AC.MIN t AC.MAX ps
8)21)
DQS/DQS low-impedance time from CK / CK t LZ.DQS t AC.MIN t AC.MAX ps
8)21)
MRS command to ODT update delay t MOD 0 12 ns
Mode register set command cycle time t MRD 2 — nCK
OCD drive mode output delay t OIT 0 12 ns
34)
DQ/DQS output hold time from DQS t QH t HP – t QHS — ps
25)
8)21)
23)24)
34)
Rev. 1.11, 2007-07 49
11172006-LBIU-F1TN