Altera External Memory PHY Interface - Manual (Page 9)

Chapter 2: Parameter Settings 2–3
© January 2010 Altera Corporation External Memory PHY Interface (ALTMEMPHY) (nonAFI) Megafunction User Guide
Table 2–1 describes the General Settings available on the Memory Settings page of
the ALTMEMPHY MegaWizard interface.
Table 2–2 describes the options available to filter the Memory Presets that are
displayed. This section is where you indicate that you are creating a datapath for
QDR II+/QDR II SRAM.
Table 2–1. General Settings
Parameter Name Description
Device family Targets device family. The device family selected here must match the device family selected on
MegaWizard page 2a.
Speed grade Selects a particular speed grade of the device (for example, 2, 3, or 4 for the Stratix III device
family).
PLL reference clock
frequency Determines the clock frequency of the external input clock to the PLL. Ensure that you use three
decimal points if the frequency is not a round number (for example, 166.667 MHz or 100 MHz) to
avoid a functional simulation or a PLL locking issue.
Memory clock
frequency Determines the memory interface clock frequency. If you are operating a memory device below its
maximum achievable frequency, ensure that you enter the actual frequency of operation rather than
the maximum frequency achievable by the memory device. Also, ensure that you use three decimal
points if the frequency is not a round number (for example, 333.333 MHz or 400 MHz) to avoid a
functional simulation or a PLL locking issue.
Controller data rate Selects the data rate for the memory controller. Sets the frequency of the controller to equal to
either the memory interface frequency (full-rate) or half of the memory interface frequency
(half-rate).
Local interface clock
frequency This field’s value depends on the memory clock frequency and controller data rate, and whether or
not you turn on the Enable Half Rate Bridge option.
Local interface width This field’s value depends on the memory clock frequency and controller data rate, and whether or
not you turn on the Enable Half Rate Bridge option.
Table 2–2. Memory Presets List
Parameter Name Description
Memory type You can filter the type of memory to display. For the ALTMEMPHY megafunction with nonAFI, select
QDR II+ SRAM and QDR II SRAM.
Memory vendor You can filter the memory types by vendor. JEDEC is also one of the options, allowing you to
choose the JEDEC specifications. If your chosen vendor is not listed, you can choose Other for QDR
II+/QDR II SRAM interfaces. Then, pick a device that has similar specifications to your chosen
device and check the values of each parameter. Make sure you change the each parameter value to
match your device specifications.
Memory format You can filter the type of memory by format (for example, components or DIMM packages). This
option is only available for DDR3, DDR2, and DDR SDRAM interfaces.
Maximum frequency You can filter the type of memory by the maximum operating frequency.