Row
Column
Data 0
Data 1
CLK
(EPI0S31)
CKE
(EPI0S30)
CSn
(EPI0S29)
WEn
(EPI0S28)
RASn
(EPI0S19)
CASn
(EPI0S18)
DQMH, DQML
(EPI0S [17:16])
AD [15:0]
(EPI0S [15:0])
Activate
NOP
Read
NOP
AD [15:0] driven in
AD [15:0] driven out
AD [15:0] driven out
Initialization and Configuration
1094
SLAU723A – October 2017 – Revised October 2018
Copyright © 2017–2018, Texas Instruments Incorporated
External Peripheral Interface (EPI)
16.4.2.5 Normal Read Cycle
shows a normal read cycle of n halfwords; n can be 1 or 2. The cycle begins with the Activate
command and the row address on the EPI0S[15:0] signals. With the programmed CAS latency of 2, the
Read command with the column address on the EPI0S[15:0] signals follows after 2 clock cycles. Following
one more NOP cycle, data is read in on the EPI0S[15:0] signals on every rising clock edge. The DQMH,
DQML, and CSn signals are deasserted after the last halfword of data is received, signaling the end of the
cycle. At least one clock period of inactivity separates any two SDRAM cycles.
Figure 16-3. SDRAM Normal Read Cycle