![](http://datasheet.mmic.net.cn/390000/MT46V64M4_datasheet_16823572/MT46V64M4_8.png)
8
256Mb: x4, x8, x16 DDR SDRAM
256Mx4x8x16DDR_B.p65
–
Rev. B; Pub. 7/00
Micron Technology, Inc., reserves the right to change products or specifications without notice.
2000, Micron Technology, Inc.
256Mb: x4, x8, x16
DDR SDRAM
ADVANCE
PIN DESCRIPTIONS (continued)
TSOP PIN NUMBERS
5, 11, 56, 62
51
16, 51
SYMBOL
DQ0-3
DQS
LDQS, UDQS
TYPE
I/O
I/O
DESCRIPTION
Data Input/Output: Data bus for x4.
Data Strobe: Output with read data, input with write data. DQS is
edge-aligned with read data, centered in write data. It is used to
capture data. For the x16 , LDQS is DQS for DQ0-DQ7 and UDQS is
DQS for DQ8-DQ15. Pin 16 is NC on x4 and x8.
DQ Power Supply: +2.5V ±0.2V. Isolated on the die for improved
noise immunity.
DQ Ground. Isolated on the die for improved noise immunity.
Power Supply: +2.5V ±0.2V.
Ground.
SSTL_2 reference voltage.
No Connect: These pins should be left unconnected.
Do Not Use: Must float to minimize noise.
3, 9, 15, 55, 61
V
DD
Q
Supply
6, 12, 52, 58, 64
1, 18, 33
34, 48, 66
49
14, 17, 19, 25, 43, 53
50
V
SS
Q
V
DD
V
SS
V
REF
NC
DNU
Supply
Supply
Supply
Supply
–
–
RESERVED NC PINS
1
TSOP PIN NUMBERS
17
19
SY MBOL
A13
QFC#
TY PE
I
O
DESCRIPTION
Address input for 1Gb devices.
FET Control: x4 only, used to control isolation switches on
modules. Open drain output. DNU on x8 or x16 option.
NOTE:
1. NC pins not listed may also be reserved for other uses now or in the future. This table simply defines specific NC pins
deemed to be of importance.