DDR2/3/mDDR
Memory
Controller
data[15:8] to/from DDR
fifo_we_in
fifo_we_out
Data Macro 1
IO 1
data[7:0] to/from DDR
fifo_we_in
fifo_we_out
Data Macro 0
IO 0
To DDR
Command Macros
VTP Macro
cmd/addr
data
data
p/n
128-bit
OCP
Where
fifo_we_out = DQS enable output for timing match between DQS and system (Memory) clock.
fifo_we_in = DQS enable input for timing match between DQS and system (Memory) clock.
EMIF
Figure 7-89. DDR2/3/mDDR Subsystem Block Diagram
7.3.3.3.1 DDR2/3/mDDR Memory Controller Interface
To move data efficiently from on-chip resources to external DDR2/3/mDDR SDRAM device, the
DDR2/3/mDDR memory controller makes use of a command FIFO, a write data FIFO, a return command
FIFO, and two Read Data FIFOs. Purpose of each FIFO is described below.
shows the block diagram of the DDR2/3/mDDR memory controller FIFOs. Commands, write
data, and read data arrive at the DDR2 memory controller parallel to each other. The same peripheral bus
is used to write and read data from external memory as well as internal memory-mapped registers.
406
Memory Subsystem
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated