DDR_CLK
DDR_CKE
DDR_CS
DDR_RAS
DDR_WE
DDR_BA[2:0]
DDR_DQM[1:0]
ACTV
DDR_A[13:0]
DDR_CAS
BANK
ROW
DDR_CLK
Architecture
377
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
DDR2/mDDR Memory Controller
14.2.3.3 Activation (ACTV)
The DDR2/mDDR memory controller automatically issues the activate (ACTV) command before a read or
write to a closed row of memory. The ACTV command opens a row of memory, allowing future accesses
(reads or writes) with minimum latency. The value of DDR_BA[2:0] selects the bank and the value of
DDR_A[13:0] selects the row. When the DDR2/mDDR memory controller issues an ACTV command, a
delay of t
RCD
is incurred before a read or write command is issued.
shows an example of an
ACTV command. Reads or writes to the currently active row and bank of memory can achieve much
higher throughput than reads or writes to random areas because every time a new row is accessed, the
ACTV command must be issued and a delay of t
RCD
incurred.
Figure 14-7. ACTV Command