MT41J128M8 MDTIC [Micon Design Technology Corporation], MT41J128M8 Datasheet - Page 167

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

Synchronous ODT Mode
ODT Latency and Posted ODT
Timing Parameters
PDF: 09005aef826aa906/Source: 09005aef82a357c3
1Gb_DDR3_5.fm - Rev. D 8/1/08 EN
Synchronous ODT mode is selected whenever the DLL is turned on and locked and
when either R
modes are:
• Any bank active with CKE HIGH
• Refresh mode with CKE HIGH
• Idle mode with CKE HIGH
• Active power-down mode (regardless of MR0[12])
• Precharge power-down mode if DLL is enabled during precharge power-down by
In synchronous ODT mode, R
HIGH by a rising clock edge and turns off ODTL off clock cycles after ODT is registered
LOW by a rising clock edge. The actual on/off times varies by
each clock edge (see Table 81 on page 168). The ODT latency is tied to the WRITE latency
(WL) by ODTL on = WL - 2 and ODTL off = WL - 2.
Since write latency is made up of CAS WRITE latency (CWL) and ADDITIVE latency (AL),
the AL programmed into the mode register (MR1[4, 3]) also applies to the ODT signal.
The DRAM’s internal ODT signal is delayed a number of clock cycles defined by the AL
relative to the external ODT signal. Thus ODTL on = CWL + AL - 2 and ODTL
off = CWL + AL - 2.
Synchronous ODT mode uses the following timing parameters: ODTL on, ODTL off,
ODTH4, ODTH8
minimum R
and ODT resistance begins to turn on. Maximum R
point at which ODT resistance is fully on. Both are measured relative to ODTL on. The
minimum R
off ODT resistance. Maximum R
has reached High-Z. Both are measured from ODTL off.
When ODT is asserted, it must remain HIGH until ODTH4 is satisfied. If a WRITE
command is registered by the DRAM with ODT HIGH, then ODT must remain HIGH
until ODTH4 (BC4) or ODTH8 (BL8) after the WRITE command (see Figure 117 on
page 169). ODTH4 and ODTH8 are measured from ODT registered HIGH to ODT regis-
tered LOW or from the registration of a WRITE command until ODT is registered LOW.
MR0[12]
TT
TT
TT
turn-on time (
turn-off time (
_
,
NOM
t
AON, and
or R
TT
_
t
167
t
t
AOF (see Table 81 and Figure 116 on page 168). The
WR
AON [MIN]) is the point at which the device leaves High-Z
TT
AOF [MIN]) is the point at which the device starts to turn
TT
turns on ODTL on clock cycles after ODT is sampled
is enabled. Based on the power-down definition, these
turn off time (
Micron Technology, Inc., reserves the right to change products or specifications without notice.
1Gb: x4, x8, x16 DDR3 SDRAM
t
AOF [MAX]) is the point at which ODT
TT
turn-on time (
On-Die Termination (ODT)
t
AON and
©2006 Micron Technology, Inc. All rights reserved.
t
AON [MAX]) is the
t
AOF around