NT5DS4M32EG-6 Просмотр технического описания (PDF) - NanoAmp Solutions, Inc.

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NT5DS4M32EG-6

1M × 32 Bits × 4 Banks Double Data Rate Synchronous RAM With Bi-Directional Data Strobe and DLL

NanoAmp Solutions, Inc. 

NanoAmp Solutions, Inc.

NT5DS4M32EG

Advance Information

FUNCTIONAL DESCRIPTION

Power-Up Sequence

DDR SDRAMs must be powered up and initialized in a predefined manner to prevent undefined operations.

1. Apply power and keep CKE at low state (All other inputs may be undefined)

- Apply VDD before or at the same time as VDDQ.

- Apply VDDQ before or at the same time as VREF & VTT

2. Start clock and maintain stable condition for minimum 200µs

3. The minimum of 200µs after stable power and clock (CK,/CK), apply NOP and CKE to be high.

4. Issue precharge command for all banks of the device.

5. Issue a EMRS command to enable DLL

*1 6. Issue a MRS command to reset DLL. The additional 200 clock cycles are required to lock the DLL.

*1,2 7. Issue precharge command for all banks of the device.

8. Issue at least 2 or more auto-refresh commands.

9. Issue a mode register set command with A8 to low to initialize the mode register.

*1 Every “DLL Enable” command resets DLL. Therefore sequence 6 can be skipped during power-up.

Instead of it, the additional 200cycles of clock input is required to lock the DLL after enabling DLL.

*2 Sequence of 6 & 7 is regardless of the order.

Figure 4: Power-Up & Initialization Sequence

/CK

CK

tRP

Command

Precharge

ALL Banks

Input must be

stable for 200us

2C lo ck

2C lo ck

min.

min.

tRP

EMRS

MRS

DLL Reset

Precharge

ALL Banks

tRF C

1st Auto

Refresh

2nd Auto

Refresh

200 Clock min.

tRF C

2C lo ck

min.

Mode

Register Set

Any

Command

Doc # 14-02-045 Rev A ECN 01-1118

6

The specifications of this device are subject to change without notice. For latest documentation see http://www.nanoamp.com.

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