Datasheet

AS4C16M32MD1
Confidential 19 Rev. 1.0/July 2014
Notes:
1. The table applies when both CKEn-1 and CKEn are HIGH, and after tXSR or tXP has been met if the
previous state was Self Refresh or Power Down.
2. DESELECT and NOP are functionally interchangeable.
3. All states and sequences not shown are illegal or reserved.
4. This command may or may not be bank specific. If all banks are being precharged, they must be in a
valid state for precharging.
5. A command other than NOP should not be issued to the same bank while a READ or WRITE burst with
Auto Precharge is enabled.
6. The new Read or Write command could be Auto Precharge enabled or Auto Precharge disabled.
7. Current State Definitions:
Idle: The bank has been precharged, and tRP has been met.
Row Active: A row in the bank has been activated, and tRCD has been met. No data
bursts/accesses and no 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.
8. The following states must not be interrupted by a command issued to the same bank. DESEDECT or NOP
commands 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 this
table, and according to next table.
Precharging: Starts with the registration of a PRECHARGE command and ends when tRP is met. Once
tRP is met, the bank will be in the idle state.
Row Activating: Starts with registration of an ACTIVE command and ends when tRCD is met. Once tRCD
is met, the bank will be in the ‘row active’ state.
Read with AP Enabled: Starts with the registration of the READ command with Auto Precharge enabled
and ends when tRP has been met. Once tRP has been met, the bank will be in the idle state.
Write with AP Enabled: Starts with registration of a WRITE command with Auto Precharge enabled and
ends when tRP has been met. Once tRP is met, the bank will be in the idle state.
9. The following states must not be interrupted by any executable command; DESEDECT or NOP commands
must be applied to each positive clock edge during these states.
Refreshing: Starts with registration of an AUTO REFRESH command and ends when tRFC is met.
Once tRFC is met, the Mobile DDR SDRAM will be in an ‘all banks idle’ state.
Accessing Mode Register: Starts with registration of a MODE REGISTER SET command and ends when
tMRD has been met. Once tMRD is met, the Mobile DDR SDRAM will be in an ‘all banks idle’ state.
Precharging All: Starts with the registration of a PRECHARGE ALL command and ends when tRP is met.