K4H510438A-TCA0 SAMSUNG [Samsung semiconductor], K4H510438A-TCA0 Datasheet - Page 14

• Manufacturer Part Number: K4H510438A-TCA0
• Description: 128Mb DDR SDRAM
• Manufacturer: SAMSUNG [Samsung semiconductor]

*1
*2
*1
128Mb DDR SDRAM
3.2 Basic Functionality
Command
3.2.1 Power-Up and Initialization Sequence
1. Apply power and attempt to maintain CKE at a low state(all other inputs may be undefined.)
2. Start clock and maintain stable condition for a minimum of 200us.
3. The minimum of 200us after stable power and clock(CK, CK), apply NOP & take CKE high.
4. Issue precharge commands for all banks of the device.
5. Issue EMRS to enable DLL.(To issue "DLL Enable" command, provide "Low" to A0, "High" to BA0 and "Low"
to all of the rest address pins, A1~A11 and BA1)
6. Issue a mode register set command for "DLL reset". The additional 200 cycles of clock input is required to
lock the DLL.
7. Issue precharge commands for all banks of the device.
8. Issue 2 or more auto-refresh commands.
9. Issue a mode register set command with low to A8 to initialize device operation.
The following sequence is required for POWER UP and Initialization.
Power up & Initialization Sequence
*1 Every "DLL enable" command resets DLL. Therefore sequence 6 can be skipped during power up.
*2 Sequence of 6 & 7 is regardless of the order.
- Apply VDD before or at the same time as VDDQ.
- Apply VDDQ before or at the same time as VTT & Vref.
(To issue DLL reset command, provide "High" to A8 and "Low" to BA0)
Instead of it, the additional 200 cycles of clock input is required to lock the DLL after enabling DLL.
CK
CK
ALL Banks
precharge
0
t
RP
1
EMRS
2
2 Clock min.
3
DLL Reset
MRS
4
2 Clock min.
Figure 4. Power up and initialization sequence
5
ALL Banks
precharge
6
t
RP
7
1st Auto
Refresh
- 14 -
8
9
t
10
RFC
11
min.200 Cycle
REV. 1.0 November. 2. 2000
12
2nd Auto
Refresh
13
14
t
RFC
15
16
Register Set
Mode
17
2 Clock min.
18
Command
Any
19