SDRAM

AS4SD16M16

AS4SD16M16

Rev. 2.6 04/13/15

Micross Components reserves the right to change products or specifications without notice.

23

NOTES:

1. This table applies when CKE

ous state was self refresh).

2. This table is bank-specific, except where noted, i.e., the current state is for a specific bank and the commands shown are those

allowed to be issued to that bank when in that state. Exceptions are covered in the notes below.

3. Current state definitions:

Idle:

The bank has been precharged, and t

Row Active:

A row in the bank has been activated, and t

register accesses are in progress.

Read:

A READ burst has been initiated, with auto precharge disabled, and has not yet terminated or been

terminated.

Write:

A WRITE burst has been initiated, with auto precharge disabled, and has not yet terminated or

been terminated.

4. The following states must not be interrupted by a command issued to the same bank. COMMAND INHIBIT or NOP com-

mands, or allowable commands to the other bank should be issued on any clock edge occurring during these states. Allowable

commands to the other bank are determined by its current state and Truth Table 3, and according to Truth Table 4.

Precharging:

Starts with registration of a PRECHARGE command and ends when t

the bank will be in the idle state.

Row Activating:

Starts with registration of an ACTIVE command and ends when t

bank will be in the row active state.

Read w/ Auto

Precharge Enabled:

Starts with registration of a READ command with auto precharge enabled and ends when t

been met. Once t

Write w/ Auto

Precharge Enabled:

Starts with registration of a WRITE command with auto precharge enabled and ends when t

been met. Once t

(continued on next page)

CURRENT STATE CS\ RAS\ CAS\ WE\

COMMAND (ACTION)

NOTES

H

X

X

X

COMMAND INHIBIT (NOP/Continue previous operation)

L

H

H

H

NO OPERATION (NOP/Continue previous operation)

L

L

H

H

ACTIVE (Select and active row)

L

L

L

H

AUTO REFRESH

7

LLLL

LOAD MODE REGISTER

7

L

L

H

L

PRECHARGE

11

L

H

L

H

READ (Select column and start READ burst)

10

L

H

L

L

WRITE (Select column and start WRITE burst)

10

L

L

H

L

PRECHARGE (Deactivate row in bank or banks)

8

L

H

L

H

READ (Select column and start new READ burst)

10

L

H

L

L

WRITE (Select column and start WRITE burst)

10

L

L

H

L

PRECHARGE (Truncate READ burst, start PRECHARGE)

8

L

H

H

L

BURST TERMINATE

9

L

H

L

H

READ (Select column and start READ burst)

10

L

H

L

L

WRITE (Select column and start new WRITE burst)

10

L

L

H

L

PRECHARGE (Truncate WRITE burst, start PRECHARGE)

8

L

H

H

L

BURST TERMINATE

9

Write

(Auto Precharge

Disabled)

ANY

Idle

Row Active

Read

(Auto Precharge

Disabled)