Datasheet

SM646UDR26485-2-I
January 31, 2006
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4
Pin Description Table
Symbol Type Polarity Function
CK0~CK2 SSTL_18 Positive
Edge
Positive line of the differential pair of system clock inputs. (All DDR2 SDRAM address and
control inputs are sampled on the rising edge of their associated clocks. Output data is ref-
erenced at the crossings of the clocks.)
CK0#~CK2# SSTL_18 Negative
Edge
Negative line of the differential pair of system clock inputs.
ODT0 SSTL_18 Active High On-Die Termination: ODT when high enables termination resistance internal to the DDR2
SDRAM. When enabled, ODT is only applied to each of the following pins: DQ, DQS, and
DM. The ODT input will be ignored if disabled in Extended Mode Register (EMRS).
CKE0 SSTL_18 Active High Activates the DDR2 SDRAM CLK signal when high and deactivates the CLK signal when
low. By deactivating the clocks, CKE low initiates the Power Down mode, or the Self
Refresh mode.
CS0# SSTL_18 Active Low Enables the associated DDR2 SDRAM command decoder when low and disables decoder
when high. When decoder is disabled, new commands are ignored but previous operations
continue.
RAS#, CAS#,
WE#
SSTL_18 Active Low When sampled at the positive rising edge of the clock, CAS#, RAS#, and WE# define the
operations to be executed by the SDRAM.
BA0, BA1 SSTL_18 - Bank Address define to which bank an Activate, Read, Write or Precharge command is
being applied. Bank address also determines if the Mode Register or Extended Mode Reg-
ister is to be accessed during a MRS or EMRS cycle.
240-pin DDR2 DIMM Pin List (Contd.)
Pin
No.
Pin
Name
Pin
No.
Pin
Name
Pin
No.
Pin
Name
Pin
No.
Pin
Name
Pin
No.
Pin
Name
Pin
No.
Pin
Name
Pin
No.
Pin
Name
Pin
No.
Pin
Name
21 DQ10 51 V
DDQ
81 DQ33 111 DQ57 141 DQ15 171 CKE1 (NC) 201 V
SS
231 V
SS
22 DQ11 52 CKE0 82 V
SS
112 V
SS
142 V
SS
172 V
DD
202 DM4 232 DM7
23 V
SS
53 V
DD
83 DQS4# 113 DQS7# 143 DQ20 173 A15(NC) 203 NC 233 NC
24 DQ16 54 BA2 (NC) 84 DQS4 114 DQS7 144 DQ21 174 A14(NC) 204 V
SS
234 V
SS
25 DQ17 55 NC 85 V
SS
115 V
SS
145 V
SS
175 V
DDQ
205 DQ38 235 DQ62
26 V
SS
56 V
DDQ
86 DQ34 116 DQ58 146 DM2 176 A12 206 DQ39 236 DQ63
27 DQS2# 57 A11 87 DQ35 117 DQ59 147 NC 177 A9 207 V
SS
237 V
SS
28 DQS2 58 A7 88 V
SS
118 V
SS
148 V
SS
178 V
DD
208 DQ44 238 V
DDSPD
29 V
SS
59 V
DD
89 DQ40 119 SDA 149 DQ22 179 A8 209 DQ45 239 SA0
30 DQ18 60 A5 90 DQ41 120 SCL 150 DQ23 180 A6 210 V
SS
240 SA1