
2–22
Altera Corporation
Stratix II Device Handbook, Volume 2
January 2008
Clock Modes
Figure 2–12 shows a TriMatrix memory block in independent clock mode.
Figure 2–12. Stratix II and Stratix II GX TriMatrix Memory Block in Independent
Clock Mode
(1)
Violating the setup or hold time on the memory block address registers could
corrupt the memory contents. This applies to both read and write operations.
6
D
ENA
Q
D
ENA
Q
D
ENA
Q
data_a[
]
address_a[
]
Memory
Block
256
×
16
(2)
512
×
8
1,024
×
4
2,04
8
×
2
4,096
×
1
Data
In
Address
A
Write/Read
Enable
Data
Out
Data
In
Address
B
Write/Read
Enable
Data
Out
enable_a
clock_a
D
ENA
Q
wren_a
6
LAB
Ro
w
Cloc
ks
q_a[
]
6
data_b[
]
address_b[
]
q_b[
]
ENA
AB
ENA
D
Q
ENA
D
Q
ENA
D
Q
D
Q
D
ENA
Q
byteena_a[
]
Byte
Enable
A
Byte
Enable
B
byteena_b[
]
ENA
D
Q
Wr
ite
Pulse
Gener
ator
Wr
ite
Pulse
Gener
ator
wren_b
enable_b
clock_b
addressstall_a
Address
Clock
Enable
A
Address
Clock
addressstall_b
Enab
le
B