
Altera Corporation
8–15
October 2007
Stratix II GX Device Handbook, Volume 2
TriMatrix Embedded Memory Blocks in Stratix II and Stratix II GX Devices
Figure 8–8. Stratix II and Stratix II GX Simple Dual-Port Timing Waveforms
(1)
The crosses in the data waveform during read mean “don’t care.”
(2)
The read enable rden signal is not available in M-RAM blocks. The M-RAM block in simple dual-port mode always
reads out the data stored at the current read address location.
True Dual-Port Mode
Stratix II and Stratix II GX M4K and M-RAM memory blocks support the
true dual-port mode. True dual-port mode supports any combination of
two-port operations: two reads, two writes, or one read and one write at
two different clock frequencies.
Figure 8–9 shows Stratix II and
Stratix II GX true dual-port memory configuration.
Figure 8–9. Stratix II and Stratix II GX True Dual-Port Memory
(1)
True dual-port memory supports input/output clock mode in addition to the
independent clock mode shown.
wrclock
wren
wraddress
q (synch)
rdclock
an-1
an
a0
a1
a2
a3
a4
a5
a6
q (asynch)
rden (2)
rdaddress
bn
b0
b1
b2
b3
doutn-2
doutn-1
doutn
doutn-1
doutn
dout0
din-1
din
din4
din5
din6
data (1)
data_a[]
address_a[]
wren_a
byteena_a[]
addressstall_a
clock_a
enable_a
aclr_a
q_a[]
data_b[]
address_b[]
wren_b
byteena_b[]
addressstall_b
clock_b
enable_b
aclr_b
q_b[]