3–18
Chapter 3: Memory Blocks in the Cyclone III Device Family
Document Revision History
Power-Up Conditions and Memory Initialization
The M9K memory block outputs of the Cyclone III device family power up to zero
(cleared) regardless of whether the output registers are used or bypassed. All M9K
memory blocks support initialization using a .mif. You can create .mifs in the
Quartus II software and specify their use using the RAM MegaWizard Plug-In
Manager when instantiating memory in your design. Even if memory is
pre-initialized (for example, using a .mif), it still powers up with its outputs cleared.
Only the subsequent read after power up outputs the pre-initialized values.
f
For more information about .mifs, refer to the Internal Memory (RAM and ROM) User
Guide and the Quartus II Handbook.
Power Management
The M9K memory block clock enables of the Cyclone III device family allow you to
control clocking of each M9K memory block to reduce AC power consumption. Use
the rdensignal to ensure that read operations only occur when necessary. If your
design does not require read-during-write, reduce power consumption by deasserting
the rdensignal during write operations, or any period when there are no memory
operations. The Quartus II software automatically powers down any unused M9K
memory blocks to save static power.
Document Revision History
Table 3–6 lists the revision history for this document.
Table 3–6. Document Revision History
Date
Version
2.3
Changes
December 2011
December 2009
July 2009
Minor text edits.
2.2
Minor changes to the text.
2.1
Made minor correction to the part number.
Updated to include Cyclone III LS information
■ Updated chapter part number.
■ Updated “Introduction” on page 3–1.
■ Updated “Overview” on page 3–1.
June 2009
2.0
■ Updated Table 3–1 on page 3–2.
■ Updated “Control Signals” on page 3–3.
■ Updated “Memory Modes” on page 3–8.
■ Updated “Simple Dual-Port Mode” on page 3–10.
■ Updated “Read or Write Clock Mode” on page 3–16.
Updated chapter to new template.
October 2008
May 2008
1.3
1.2
■ Revised the maximum performance of the M9K blocks to 315 MHz in “Introduction” and
“Overview” sections, and in Table 3-1.
■ Updated “Address Clock Enable Support” section.
Added chapter TOC and “Referenced Documents” section.
Initial release.
July 2007
1.1
1.0
March 2007
Cyclone III Device Handbook
Volume 1
December 2011 Altera Corporation
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