MT46V128M4TG-8 データシートの表示（PDF） - Micron Technology
部品番号
コンポーネント説明
メーカー
MT46V128M4TG-8 Datasheet PDF : 68 Pages
| |||
Read Latency
The READ latency is the delay, in clock cycles, be-
tween the registration of a READ command and the
availability of the first bit of output data. The latency
can be set to 2, or 2.5 clocks, as shown in Figure 2.
If a READ command is registered at clock edge n,
and the latency is m clocks, the data will be available
nominally coincident with clock edge n + m. Table 2
indicates the operating frequencies at which each CAS
latency setting can be used.
Reserved states should not be used as unknown
operation or incompatibility with future versions may
result.
CK#
CK
COMMAND
T0
READ
DQS
DQ
CK#
CK
COMMAND
T0
READ
DQS
DQ
T1
NOP
CL = 2
T2 T2n T3 T3n
NOP
NOP
T1
T2 T2n T3 T3n
NOP
NOP
NOP
CL = 2.5
Burst Length = 4 in the cases shown
Shown with nominal tAC and nominal tDSDQ
TRANSITIONING DATA
DON’T CARE
ADVANCE
512Mb: x4, x8, x16
DDR SDRAM
Table 2
CAS Latency (CL)
SPEED
-75Z
-75
-8
ALLOWABLE OPERATING
FREQUENCY (MHz)
CL = 2
75 ≤ f ≤ 133
75 ≤ f ≤ 100
75 ≤ f ≤ 100
CL = 2.5
75 ≤ f ≤133
75 ≤ f ≤133
75 ≤ f ≤125
Operating Mode
The normal operating mode is selected by issuing a
MODE REGISTER SET command with bits A7-A12 each
set to zero, and bits A0-A6 set to the desired values. A
DLL reset is initiated by issuing a MODE REGISTER
SET command with bits A7 and A9-A12 each set to zero,
bit A8 set to one, and bits A0-A6 set to the desired
values. Although not required by the Micron device,
JEDEC specifications recommend when a LOAD MODE
REGISTER command is issued to reset the DLL, it
should always be followed by a LOAD MODE REGIS-
TER command to select normal operating mode.
All other combinations of values for A7-A12 are re-
served for future use and/or test modes. Test modes
and reserved states should not be used because un-
known operation or incompatibility with future ver-
sions may result.
Figure 2
CAS Latency
512Mb: x4, x8, x16 DDR SDRAM
512Mx4x8x16DDR_B.p65 – Rev. B; Pub 4/01
11
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2001, Micron Technology, Inc.
Share Link: 