PC-133 HSDRAM
256MB, 512MB DIMM
Pin Descriptions
Symbol
CK0,1,2,3
CKE0,1
Preliminary Data Sheet
Type
Input
Input
Function
Clocks: All SDRAM input signals are sampled on the positive edge of CK.
Clock Enables: CKE activate (high) or deactivate (low) the CK signals. Deactivating the clock initiates the
Power-Down and Self-Refresh operations (all banks idle), or Clock Suspend operation. CKE is synchronous until
the device enters Power-Down and Self-Refresh modes where it is asynchronous until the mode is exited.
Chip Select: S# enables (low) or disables (high) the command decoder. When the command decoder is
disabled, new commands are ignored but previous operations continue.
Command Inputs: Sampled on the rising edge of CK, these inputs define the command to be executed.
Bank Addresses: These inputs define to which of the 4 banks a given command is being applied.
Address Inputs: A0-A12 define the row address during the Bank Activate command. A0-A9 define the column
address during Read and Write commands. A10/AP invokes the Auto-precharge operation. During manual
Precharge commands, A10/AP low specifies a single bank precharge while A10/AP high precharges all banks.
The address inputs are also used to program the Mode Register.
Data I/O: Data bus inputs and outputs. For Write cycles input data is applied to these pins and must be set-up
and held relative to the rising edge of clock. For Read cycles, the device drives output data on these pins after
the CAS latency is satisfied.
Data I/O Mask Inputs: DQMB0-7 inputs mask write data (zero latency) and acts as a synchronous output enable
(2-cycle latency) for read data.
ECC Check Bits
Power Supply: +3.3 V
Ground
Serial Presence-Detect Data: SDA is a bi-directional pin used to transfer addresses and data into and data out of
the presence-detect portion of the module.
Serial Clock for Presence-Detect: SCL is used to synchronize the presence detect data transfer to
and from the module
Presence-Detect Address Inputs: These pins are used to configure the presence detect device.
Serial Presence Detect Write Protect: Active high inhibits writes to the SPD EEPROM. WP must be driven low
for normal read/write operations.
Reserved for Future Use: These pins should be left unconnected.
Do not use.
No connect - open pin.
S0,1,2,3#
RAS#, CAS#,
WE#
BA1, BA0
A0-A12
Input
Input
Input
Input
DQ0-DQ63
Input/
Output
Input
Input/
Output
Supply
Supply
Input/
Output
Input
Input
Input
-
-
-
DQMB0-7
CB0-7
V
DD
V
SS
SDA
SCL
SA0-2
WP
RFU
DU
NC
Enhanced Memory Systems Inc., 1850 Ramtron Dr., Colo Spgs, CO 80921
PHONE: (800) 545-DRAM; FAX: (719) 488-9095;
http://www.edram.com
1999 Enhanced Memory Systems. All rights reserved.
The information contained herein is subject to change without notice.
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Revision 1.0
RAMTRON [ RAMTRON INTERNATIONAL CORPORATION ]
