User guide

Chapter 3: Parameter Settings 3–15
DDR3 SDRAM Controller with ALTMEMPHY Parameter Settings
December 2010 Altera Corporation External Memory Interface Handbook Volume 3
Section II. DDR3 SDRAM Controller with ALTMEMPHY IP User Guide
Table 3–8. Controller Settings (Part 1 of 3)
Parameter Controller Architecture Description
Controller architecture — Specifies the controller architecture.
Enable self-refresh controls Both
Turn on to enable the controller to allow you to have control on
when to place the external memory device in self-refresh mode,
refer to “User-Controlled Self-Refresh Logic” on page 7–8
(HPC II).
Enable power down controls HPC
Turn on to enable the controller to allow you to have control on
when to place the external memory device in power-down mode.
Enable auto power down HPC II
Turn on to enable the controller to automatically place the
external memory device in power-down mode after a specified
number of idle controller clock cycles is observed in the
controller. You can specify the number of idle cycles after which
the controller powers down the memory in the Auto Power
Down Cycles field, refer to “Automatic Power-Down with
Programmable Time-Out” on page 7–7.
Auto power down cycles HPC II
Determines the desired number of idle controller clock cycles
before the controller places the external memory device in a
power-down mode. The legal range is 1 to 65,535.
The auto power-down mode is disabled if you set the value to 0
clock cycles.
Enable user auto-refresh
controls
Both
Turn on to enable the controller to allow you to issue a single
refresh.
Enable auto-precharge
control
HPC
Turn on to enable the auto-precharge control on the controller
top level. Asserting the auto-precharge control signal while
requesting a read or write burst allows you to specify whether or
not the controller should close (auto-precharge) the current
opened page at the end of the read or write burst.
Local-to-memory address
mapping
HPC II
Allows you to control the mapping between the address bits on
the Avalon interface and the chip, row, bank, and column bits on
the memory interface.
If your application issues bursts that are greater than the
column size of the memory device, choose the
Chip-Row-Bank-Column option. This option allows the
controller to use its look-ahead bank management feature to
hide the effect of changing the currently open row when the
burst reaches the end of the column.
On the other hand, if your application has several masters that
each use separate areas of memory, choose the
Chip-Bank-Row-Column option. This option allows you to use
the top address bits to allocate a physical bank in the memory to
each master. The physical bank allocation avoids different
masters accessing the same bank which is likely to cause
inefficiency, as the controller must then open and close rows in
the same bank.
Command queue look-ahead
depth
HPC II
Specifies a command queue look-ahead depth value to control
the number of read or write requests the look-ahead bank
management logic examines, refer to “Command Queue” on
page 7–4.