MT4LSDT864AY-13EG2 Micron Technology Inc, MT4LSDT864AY-13EG2 Datasheet - Page 8

• Manufacturer Part Number: MT4LSDT864AY-13EG2
• Description: MODULE SDRAM 64MB 168-DIMM
• Manufacturer: Micron Technology Inc

Specifications of MT4LSDT864AY-13EG2

• Memory Type: SDRAM
• Memory Size: 64MB
• Speed: 133MHz
• Package / Case: 168-DIMM
• Main Category: DRAM Module
• Sub-category: SDRAM
• Module Type: 168UDIMM
• Device Core Size: 64b
• Organization: 8Mx64
• Total Density: 64MByte
• Chip Density: 128Mb
• Access Time (max): 5.4ns
• Maximum Clock Rate: 133MHz
• Operating Supply Voltage (typ): 3.3V
• Operating Current: 660mA
• Number Of Elements: 4
• Operating Supply Voltage (max): 3.6V
• Operating Supply Voltage (min): 3V
• Operating Temp Range: 0C to 65C
• Operating Temperature Classification: Commercial
• Pin Count: 168
• Mounting: Socket
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Mode Register Definition
Burst Length (BL)
PDF: 09005aef8078bc7c/Source: 09005aef8078bcd3
SD4C4_8_16X64AG.fm - Rev. D 1/07 EN
defined as a signal cycling within timing constraints specified for the clock pin), the
SDRAM requires a 100µs delay prior to issuing any command other than a COMMAND
INHIBIT or NOP . Starting at some point during this 100µs period and continuing at least
through the end of this period, COMMAND INHIBIT or NOP commands should be
applied.
Once the 100µs delay has been satisfied with at least one COMMAND INHIBIT or NOP
command having been applied, a PRECHARGE command should be applied. All device
banks must then be precharged, thereby placing the device in the all banks idle state.
Once in the idle state, two AUTO REFRESH cycles must be performed. After the AUTO
REFRESH cycles are complete, the SDRAM is ready for mode register programming.
Because the mode register will power up in an unknown state, it should be loaded prior
to applying any operational command.
The mode register is used to define the specific mode of operation of the SDRAM. This
definition includes the selection of a burst length, a burst type, a CAS latency, an oper-
ating mode, and a write burst mode, as shown in Figure 4 on page 10. The mode register
is programmed via the LOAD MODE REGISTER command and will retain the stored
information until it is programmed again or the device loses power.
Mode register bits M0–M2 specify the burst length, M3 specifies the type of burst
(sequential or interleaved), M4–M6 specify the CAS latency, M7 and M8 specify the oper-
ating mode, M9 specifies the write burst mode, and M10 and M11 are reserved for future
use. For the 128MB module, address A12 (M12) is undefined but should be driven LOW
during loading of the mode register.
The mode register must be loaded when all device banks are idle, and the controller
must wait the specified time before initiating the subsequent operation. Violating either
of these requirements will result in unspecified operation.
Read and write accesses to the SDRAM are burst oriented, with the burst length being
programmable, as shown in Figure 4 on page 10. The burst length determines the
maximum number of column locations that can be accessed for a given READ or WRITE
command. Burst lengths of 1, 2, 4, or 8 locations are available for both the sequential and
the interleaved burst types, and a full-page burst is available for the sequential type. The
full-page burst is used in conjunction with the BURST TERMINATE command to
generate arbitrary burst lengths.
Reserved states should not be used, as unknown operation or incompatibility with
future versions may result.
When a READ or WRITE command is issued, a block of columns equal to the burst
length is effectively selected. All accesses for that burst take place within this block,
meaning that the burst will wrap within the block if a boundary is reached, as shown in
Table 6 on page 11. The block is uniquely selected by A1–Ai when BL = 2, A2–Ai when BL
= 4, and A3–Ai when BL = 8. See note 8 of Table 6 on page 11 for Ai values. The remaining
(least significant) address bit(s) is (are) used to select the starting location within the
block. Full-page bursts wrap within the page if the boundary is reached, as shown in
Table 6 on page 11.
32MB, 64MB, 128MB (x64, SR) 168-Pin SDRAM UDIMM
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Micron Technology, Inc., reserves the right to change products or specifications without notice.
Mode Register Definition
©2002 Micron Technology, Inc. All rights reserved.