EP3C16F256I7N Altera, EP3C16F256I7N Datasheet - Page 45

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

Chapter 3: Memory Blocks in the Cyclone III Device Family
Memory Modes
© December 2009
Altera Corporation
During a write operation, the behavior of the RAM outputs is configurable. If you
activate rden during a write operation, the RAM outputs show either the new data
being written or the old data at that address. If you perform a write operation with
rden deactivated, the RAM outputs retain the values they held during the most
recent active rden signal.
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 read-during-write mode, refer to
Operations” on page
The port width configurations for M9K blocks in single-port mode are as follow:
■
■
■
■
■
■
■
■
■
Figure 3–8
mode with unregistered outputs. Registering the outputs of the RAM simply delays
the q output by one clock cycle.
Figure 3–8. Cyclone III Device Family Single-Port Mode Timing Waveforms
8192 × 1
4096 × 2
2048 × 4
1024 × 8
1024 × 9
512 × 16
512 × 18
256 × 32
256 × 36
q_a (new data)
q_a (old data)
address_a
wren_a
rden_a
data_a
shows timing waveforms for read and write operations in single-port
clk_a
3–16.
A
a0(old data)
A
a0
B
B
A
C
C
B
D
a1(old data)
D
Cyclone III Device Handbook, Volume 1
a1
“Read-During-Write
E
E
D
F
F
E
3–9