Truth Table a: Commands

1.CKE is high for all commands shown except Self Refresh.

2.BA0, BA1 select either the Base or the Extended Mode Register (BA0 = 0, BA1 = 0 selects Mode Register; BA0 = 1, BA1 = 0 selects ,Extended Mode Register; other combinations of BA0-BA1 are reserved; A0-A12 provide the op-code to be written to the selected Mode Register.)

3.BA0-BA1 provide bank address and A0-A12 provide row address.

4.BA0, BA1 provide bank address; A0-Aiprovide column address (where i = 9 for x8 and 9, 11 for x4); A10 high enables the Auto Precharge feature (non-persistent), A10 low disables the Auto Precharge feature.

5.A10 LOW: BA0, BA1 determine which bank is precharged.A10 HIGH: all banks are precharged and BA0, BA1 are “Don’t Care.”

6.This command is auto refresh if CKE is high; Self Refresh if CKE is low.

7.Internal refresh counter controls row and bank addressing; all inputs and I/Os are “Don’t Care” except for CKE.

8.Applies only to read bursts with Auto Precharge disabled; this command is undefined (and should not be used) for read bursts with Auto Precharge enabled or for write bursts

9.Deselect and NOP are functionally interchangeable.

Active

The Active command is used to open (or activate) a row in a particular bank for a subsequent access. The value on the BA0,BA1 inputs selects the bank, and the address provided on inputs A0-A12 selects the row. This row remains active (or open) for accesses until a Precharge (or Read or Write with Auto Precharge) is issued to that bank. A Precharge (or Read or Write with Auto Precharge) command must be issued and completed before opening a different row in the same bank.

CONFIDENTIAL – DO NOT COPY

Page 7-50

 

File No. SG-0198

Page 69
Image 69
Vizio L42HDTV10A, GV42L HDTV service manual Truth Table a Commands, Active