Altera DDR SDRAM High-Performance Controllers and ALTMEMPHY IP - Manual (Page 7)

June 2011 Altera Corporation External Memory Interface Handbook Volume 3
Section I. DDR and DDR2 SDRAM Controllers with ALTMEMPHY IP User Guide
1. About This IP
The Altera
®
DDR and DDR2 SDRAM Controllers with ALTMEMPHY IP provide
simplified interfaces to industry-standard DDR SDRAM and DDR2 SDRAM. The
ALTMEMPHY megafunction is an interface between a memory controller and the
memory devices, and performs read and write operations to the memory. The DDR
and DDR2 SDRAM Controllers with ALTMEMPHY IP work in conjunction with the
Altera ALTMEMPHY megafunction.
The DDR and DDR2 SDRAM Controllers with ALTMEMPHY IP and ALTMEMPHY
megafunction offer full-rate or half-rate DDR and DDR2 SDRAM interfaces. The DDR
and DDR2 SDRAM Controllers with ALTMEMPHY IP offer the high-performance
controller II (HPC II), which provides high efficiency and advanced features.
Figure 1–1 shows a system-level diagram including the example top-level file that the
DDR or DDR2 SDRAM Controller with ALTMEMPHY IP creates for you.
The MegaWizard ™ Plug-In Manager generates an example top-level file, consisting of
an example driver and your DDR or DDR2 SDRAM high-performance controller
custom variation. The controller instantiates an instance of the ALTMEMPHY
megafunction which in turn instantiates a phase-locked loop (PLL) and DLL. You can
also instantiate the DLL outside the ALTMEMPHY megafunction to share the DLL
between multiple instances of the ALTMEMPHY megafunction. You cannot share a
PLL between multiple instances of the ALTMEMPHY megafunction, but you may
share some of the PLL clock outputs between these multiple instances.
The example top-level file is a fully-functional design that you can simulate,
synthesize, and use in hardware. The example driver is a self-test module that issues
read and write commands to the controller and checks the read data to produce the
pass or fail, and test complete signals.
The ALTMEMPHY megafunction creates the datapath between the memory device
and the memory controller. The megafunction is available as a stand-alone product or
can be used in conjunction with Altera high-performance memory controllers. When
using the ALTMEMPHY megafunction as a stand-alone product, use with either
custom or third-party controllers.
Figure 1–1. System-Level Diagram
Note to Figure 1–1 :
(1) When you choose Instantiate DLL Externally, delay-locked loop (DLL) is instantiated outside the ALTMEMPHY
megafunction.
Pass or Fail
External
Memory
Device
ALTMEMPHY
High-
Performance
Controller
Example
Driver
PLL
(1)
Example Top-Level File
DLL