EP3C16F256I7N Altera, EP3C16F256I7N Datasheet - Page 48

• Manufacturer Part Number: EP3C16F256I7N
• Description: Cyclone III
• Manufacturer: Altera

3–12
Cyclone III Device Handbook, Volume 1
Table 3–4
Table 3–4. Cyclone III Device Family M9K Block Mixed-Width Configurations (True Dual-Port
Mode)
In true dual-port mode, M9K memory blocks support separate wren and rden
signals. You can save power by keeping the rden signal low (inactive) when not
reading. Read-during-write operations to the same address can either output “New
Data” at that location or “Old Data”. To choose the desired behavior, set the
Read-During-Write option to either New Data or Old Data in the RAM MegaWizard
Plug-In Manager in the Quartus II software. For more information about this
behavior, refer to
In true dual-port mode, you can access any memory location at any time from either
port A or port B. However, when accessing the same memory location from both
ports, you must avoid possible write conflicts. When you attempt to write to the same
address location from both ports at the same time, a write conflict happens. This
results in unknown data being stored to that address location. There is no conflict
resolution circuitry built into the Cyclone III device family M9K memory blocks. You
must handle address conflicts external to the RAM block.
8192
4096
2048
1024
512
1024
512
Read Port
× 16
× 18
× 1
× 2
× 4
× 8
× 9
lists the possible M9K block mixed-port width configurations.
8192
v
v
v
v
v
—
—
“Read-During-Write Operations” on page
× 1
4096
v
v
v
v
v
—
—
× 2
2048
v
v
v
v
v
—
—
× 4
Chapter 3: Memory Blocks in the Cyclone III Device Family
Write Port
1024
v
v
v
v
v
—
—
× 8
512
© December 2009 Altera Corporation
v
v
v
v
v
—
—
× 16
3–16.
1024
v
v
—
—
—
—
—
× 9
Memory Modes
512
—
—
—
—
—
v
v
× 18