MT41J128M8 MDTIC [Micon Design Technology Corporation], MT41J128M8 Datasheet - Page 139

• Manufacturer Part Number: MT41J128M8
• Description: 1Gb: x4, x8, x16 DDR3 SDRAM
• Manufacturer: MDTIC [Micon Design Technology Corporation]

WRITE
PDF: 09005aef826aa906/Source: 09005aef82a357c3
1Gb_DDR3_4.fm - Rev. D 8/1/08 EN
WRITE bursts are initiated with a WRITE command. The starting column and bank
addresses are provided with the WRITE command, and auto precharge is either enabled
or disabled for that access. If auto precharge is selected, the row being accessed will be
precharged at the end of the WRITE burst. If auto precharge is not selected, the row will
remain open for subsequent accesses. After a WRITE command has been issued, the
WRITE burst may not be interrupted. For the generic WRITE commands used in
Figure 86 on page 141 through Figure 94 on page 146, auto precharge is disabled.
During WRITE bursts, the first valid data-in element is registered on a rising edge of DQS
following the WRITE latency (WL) clocks later and subsequent data elements will be
registered on successive edges of DQS. WRITE latency (WL) is defined as the sum of
POSTED CAS ADDITIVE latency (AL) and CAS WRITE latency (CWL): WL = AL + CWL.
The values of AL and CWL are programmed in the MR0 and MR2 registers, respectively.
Prior to the first valid DQS edge, a full cycle is needed (including a dummy crossover of
DQS, DQS#) and specified as the WRITE preamble shown in Figure 86 on page 141. The
half cycle on DQS following the last data-in element is known as the WRITE postamble.
The time between the WRITE command and the first valid edge of DQS is WL clocks
±
where
t
Data may be masked from completing a WRITE using data mask. The mask occurs on
the DM ball aligned to the write data. If DM is LOW, the write completes normally. If DM
is HIGH, that bit of data is masked.
Upon completion of a burst, assuming no other commands have been initiated, the DQ
will remain High-Z, and any additional input data will be ignored.
Data for any WRITE burst may be concatenated with a subsequent WRITE command to
provide a continuous flow of input data. The new WRITE command can be
following the previous WRITE command. The first data element from the new burst is
applied after the last element of a completed burst. Figures 87 and 88 on page 142 show
concatenated bursts. An example of nonconsecutive WRITEs is shown in Figure 89 on
page 143.
Data for any WRITE burst may be followed by a subsequent READ command after
has been met (see Figures 90 and 91 on page 144 and Figure 92 on page 145).
Data for any WRITE burst may be followed by a subsequent PRECHARGE command
providing
page 146.
Both
(fixed BC4, BL8 vs. OTF).
DQSS (MAX) cases.
t
DQSS. Figure 87 on page 142 through Figure 94 on page 146 show the nominal case
t
WTR and
t
DQSS = 0ns; however, Figure 86 on page 141 includes
t
WR has been met, as shown in Figure 93 on page 146 and Figure 94 on
t
WR starting time may vary depending on the mode register settings
139
Micron Technology, Inc., reserves the right to change products or specifications without notice.
1Gb: x4, x8, x16 DDR3 SDRAM
t
DQSS (MIN) and
©2006 Micron Technology, Inc. All rights reserved.
Operations
t
CCD clocks
t
WTR