RAM Blocks Operations
Figure 2-6: Byte Enable Functional Waveform
This figure shows how the
wren
and
byteena
signals control the operations of the RAM blocks. For the
M10K blocks, the write-masked data byte output appears as a “don’t care” value because the “current data”
value is not supported.
inclock
wren
address
data
byteena
contents at a0
contents at a1
contents at a2
contents at a3
contents at a4
don’t care: q (asynch)
current data: q (asynch)
an
a0
a1
a2
a3
a4
a0
XXXXXXXX
XXXXXXXX
ABCDEF12
ABCDEF12
XXXX
XXXX
1000
0100
0010
0001
1111
FFFFFFFF
FFFFFFFF
FFFFFFFF
FFFFFFFF
FFFFFFFF
FFFFFF12
FFFFFF12
FFFFEFFF
FFFFEFFF
FFCDFFFF
FFCDFFFF
ABFFFFFF
ABFFFFFF
ABFFFFFF
doutn
doutn
ABXXXXXX
XXCDXXXX
XXXXEFXX
XXXXXX12
ABCDEF12
ABFFFFFF
ABCDEF12
Memory Blocks Packed Mode Support
The M10K memory blocks support packed mode.
The packed mode feature packs two independent single-port RAM blocks into one memory block. The
Quartus II software automatically implements packed mode where appropriate by placing the physical RAM
block in true dual-port mode and using the MSB of the address to distinguish between the two logical RAM
blocks. The size of each independent single-port RAM must not exceed half of the target block size.
Memory Blocks Address Clock Enable Support
The embedded memory blocks support address clock enable, which holds the previous address value for as
long as the signal is enabled (
addressstall = 1
). When the memory blocks are configured in dual-port
mode, each port has its own independent address clock enable. The default value for the address clock enable
signal is low (disabled).
Altera Corporation
Embedded Memory Blocks in Cyclone V Devices
2-15
RAM Blocks Operations
CV-52002
2013.05.06