mt18vddt12872phg-335 Micron Semiconductor Products, mt18vddt12872phg-335 Datasheet - Page 20
![no-image](/images/no-image-200.jpg)
mt18vddt12872phg-335
Manufacturer Part Number
mt18vddt12872phg-335
Description
1gb X72, Ecc, Pll 200-pin Ddr Sdram Sodimm
Manufacturer
Micron Semiconductor Products
Datasheet
1.MT18VDDT12872PHG-335.pdf
(28 pages)
Initialization
tialized as described below:
pdf: 09005aef81697898/source: 09005aef8169786e
DD18C128x72PHG.fm - Rev. A 10/04 EN
10. Wait at least
11. Using the LMR command program the Mode Reg-
12. Wait at least
13. Issue a PRECHARGE ALL command.
14. Wait at least
15. Issue an AUTO REFRESH command (Note this
16. Wait at least
17. Issue an AUTO REFRESH command (Note this
18. Wait at least
19. Although not required by the Micron device,
20. Wait at least
21. At this point the DRAM is ready for any valid com-
1. Simultaneously apply power to V
2. Apply V
3. Assert and hold CKE at a LVCMOS logic low.
4. Provide stable CLOCK signals.
5. Wait at least 200µs.
6. Bring CKE high and provide at least one NOP or
7. Perform a PRECHARGE ALL command.
8. Wait at least
9. Using the LMR command program the Extended
To ensure device operation the DRAM must be ini-
DESELECT command. At this point the CKE input
changes from a LVCMOS input to a SSTL2 input
only and will remain a SSTL_2 input unless a
power cycle occurs.
DESELECT commands must be given.
Mode Register (E0 = 0 to enable the DLL and E1 =
0 for normal drive or E1 = 1 for reduced drive, E2
through En must be set to 0; where n = most sig-
nificant bit).
commands are allowed.
ister to set operating parameters and to reset the
DLL. Note at least 200 clock cycles are required
between a DLL reset and any READ command.
commands are allowed.
commands are allowed.
may be moved prior to step 13).
commands are allowed.
may be moved prior to step 13).
commands are allowed.
JEDEC requires a LMR command to clear the DLL
bit (set M8 = 0). If a LMR command is issued the
same operating parameters should be utilized as
in step 11.
commands are allowed.
mand. Note 200 clock cycles are required between
step 11 (DLL Reset) and any READ command.
REF
and then V
t
t
t
t
t
MRD time, only NOPs or DESELECT
MRD time, only NOPs or DESELECT
MRD time, only NOPs or DESELECT
t
t
RFC time, only NOPs or DESELECT
RFC time, only NOPs or DESELECT
RP time, during this time NOPs or
RP time, only NOPs or DESELECT
TT
power.
DD
and V
DD
Q.
20
Figure 10: Initialization Flow Diagram
200-PIN DDR SDRAM SODIMM
Micron Technology, Inc., reserves the right to change products or specifications without notice.
Step
10
11
12
13
14
15
16
17
18
19
20
21
1
2
3
4
5
6
7
8
9
Configure Load Mode Register and reset DLL
Assert NOP or DESELECT commands for t RFC
Optional LMR command to clear DLL bit
Assert NOP or DESELECT for t MRD time
Assert NOP or DESELECT for t MRD time
Assert NOP or DESELECT for t MRD time
DRAM is ready for any valid command
Assert NOP or DESELECT for t RFC time
Bring CKE High with a NOP command
Assert NOP or DESELECT for t RP time
Assert NOP or DESELECT for t RP time
Configure Extended Mode Register
Issue AUTO REFRESH command
Issue AUTO REFRESH command
CKE must be LVCMOS Low
1GB (x72, ECC, PLL)
V
Apply stable CLOCKs
Wait at least 200us
Apply V
DD
PRECHARGE ALL
PRECHARGE ALL
and V
REF
©2004 Micron Technology, Inc. All rights reserved.
DD
and V
Q Ramp
TT