EP1C20F ALTERA [Altera Corporation], EP1C20F Datasheet - Page 31

• Manufacturer Part Number: EP1C20F
• Description: Cyclone FPGA Family
• Manufacturer: ALTERA [Altera Corporation]

Figure 2–17. Independent Clock Mode
Notes to
(1)
(2)
Altera Corporation
May 2008
clken
clock
wren
A
A
A
data
byteena
address
All registers shown have asynchronous clear ports.
Violating the setup or hold time on the address registers could corrupt the memory contents. This applies to both
read and write operations.
A
[ ]
6
A
Figure
A
[ ]
[ ]
6 LAB Row Clocks
2–17:
D
ENA
D
ENA
D
ENA
D
ENA
Q
Q
Q
Q
Independent Clock Mode
The M4K memory blocks implement independent clock mode for true
dual-port memory. In this mode, a separate clock is available for each port
(ports A and B). Clock A controls all registers on the port A side, while
clock B controls all registers on the port B side. Each port, A and B, also
supports independent clock enables and asynchronous clear signals for
port A and B registers.
independent clock mode.
Input/Output Clock Mode
Input/output clock mode can be implemented for both the true and
simple dual-port memory modes. On each of the two ports, A or B, one
clock controls all registers for inputs into the memory block: data input,
wren, and address. The other clock controls the block's data output
registers. Each memory block port, A or B, also supports independent
clock enables and asynchronous clear signals for input and output
registers.
clock mode.
Generator
Write
Pulse
Figures 2–18
D
ENA
Notes
Data In
Byte Enable A
Address A
Write/Read
Enable
Data Out
Q
A
(1),
Memory Block
256 ´ 16 (2)
q
1,024 ´ 4
2,048 ´ 2
4,096 ´ 1
A
512 ´ 8
[ ]
(2)
and
q
Figure 2–17
B
[ ]
Byte Enable B
Write/Read
Address B
2–19
Data Out
Data In
Enable
B
Q
ENA
show the memory block in input/output
D
shows an M4K memory block in
Generator
Write
Pulse
Q
Q
Q
Q
ENA
ENA
ENA
ENA
D
D
D
D
Embedded Memory
Preliminary
6
data
byteena
address
wren
clken
clock
2–25
B
B
B
B
[ ]
B
B
[ ]
[ ]