Datasheet

AS4C16M32MD1
Confidential 25 Rev. 1.0/July 2014
7.5. Read
The READ command (see Figure 12) is used to initiate a burst read access to an active row, with a
burst length as set in the Mode Register. BA0 and BA1 select the bank, and the address inputs
select the starting column location. The value of A10 determines whether or not Auto Precharge is
used. If Auto Precharge is selected, the row being accessed will be precharged at the end of the
read burst; if Auto Precharge is not selected, the row will remain open for subsequent accesses.
The basic Read timing parameters for DQs are shown in Figure 13; they apply to all Read
operations.
During Read bursts, DQS is driven by the LPDDR SDRAM along with the output data. The initial Low
state of the DQS is known as the read preamble; the Low state coincident with last data-out
element is known as the read postamble. The first data-out element is edge aligned with the first
rising edge of DQS and the successive data-out elements are edge aligned to successive edges of
DQS. This is shown in Figure 14 with a CAS latency of 2 and 3.
Upon completion of a read burst, assuming no other READ command has been initiated, the DQs
will go to High-Z.