![](http://datasheet.mmic.net.cn/390000/MT48LC1M16A1S_datasheet_16823579/MT48LC1M16A1S_5.png)
16Mb: x16 SDRAM
16MSDRAMx16.p65
–
Rev. 8/99
Micron Technology, Inc., reserves the right to change products or specifications without notice.
1999, Micron Technology, Inc.
5
16Mb: x16
SDRAM
PIN DESCRIPTIONS
PIN NUMBERS
35
SY MBOL
CLK
TY PE
Input
DESCRIPTION
Clock: CLK is driven by the system clock. All SDRAM input signals are
sampled on the positive edge of CLK. CLK also increments the internal
burst counter and controls the output registers.
Clock Enable: CKE activates (HIGH) and deactivates (LOW) the CLK
signal. Deactivating the clock provides PRECHARGE POWER-DOWN
and SELF REFRESH operations (all banks idle), ACTIVE POWER-DOWN
(row ACTIVE in either bank) or CLOCK SUSPEND operation (burst/access
in progress). CKE is synchronous except after the device enters power-
down and self refresh modes, where CKE becomes asynchronous until
after exiting the same mode. The input buffers, including CLK, are
disabled during power-down and self refresh modes, providing low
standby power. CKE may be tied HIGH.
Chip Select: CS# enables (registered LOW) and disables (registered
HIGH) the command decoder. All commands are masked when CS# is
registered HIGH. CS# provides for external bank selection on systems
with multiple banks. CS# is considered part of the command code.
Command Inputs: RAS#, CAS# and WE# (along with CS#) define the
command being entered.
Input/Output Mask: DQM is an input mask signal for write accesses and an
output enable signal for read accesses. Input data is masked when
DQM is sampled HIGH during a WRITE cycle. The output buffers are
placed in a High-Z state (two-clock latency) when DQM is sampled
HIGH during a READ cycle. DQML corresponds to DQ0-DQ7; DQMH
corresponds to DQ8-DQ15.
DQML and DQMH are considered same state when referenced as DQM.
Bank Address Inputs: BA defines to which bank the ACTIVE, READ,
WRITE or PRECHARGE command is being applied. BA is also used to
program the twelfth bit of the Mode Register.
Address Inputs: A0-A10 are sampled during the ACTIVE command
(row-address A0-A10) and READ/WRITE command (column-address A0-
A7, with A10 defining AUTO PRECHARGE) to select one location out of
the 512K available in the respective bank. A10 is sampled during a
PRECHARGE command to determine if all banks are to be precharged
(A10 HIGH). The address inputs also provide the op-code during a
LOAD MODE REGISTER command.
Input/ Data I/Os: Data bus.
Output
34
CKE
Input
18
CS#
Input
15, 16, 17
WE#, CAS#,
RAS#
DQML,
DQMH
Input
14, 36
Input
19
BA
Input
21-24, 27-32, 20
A0-A10
Input
2, 3, 5, 6, 8, 9,
11, 12, 39, 40, 42,
43, 45, 46, 48, 49
33, 37
7, 13, 38, 44
DQ0-
DQ15
NC
V
DD
Q
–
No Connect: These pins should be left unconnected.
Supply DQ Power: Provide isolated power to DQs for improved noise immu-
nity.
Supply DQ Ground: Provide isolated ground to DQs for improved noise
immunity.
Supply Power Supply: +3.3V ±0.3V.
Supply Ground.
4, 10, 41, 47
V
SS
Q
1, 25
26, 50
V
DD
V
SS