Altera First-In-First-Out Partitioner User Manual
Page 19

Altera Corporation
17
Getting Started
FIFO Partitioner Megafunction User Guide
clk_port_a_n
Yes
In
Clock for port a
of FIFO n
Write side FIFO port clock. One per write port.
clk_port_b_n
Yes
In
Clock for port b
of FIFO n
Read side FIFO port clock. One per read port.
wr_data_a_n[]
Yes
In
Port a data bus
for FIFO n
Write side data port. One per write port.
wr_en_a_n
Yes
In
Port a write
enable signal for
FIFO n
One per FIFO. The user is restricted from
asserting the
wr_en_a_n
for a FIFO whose
wr_full_n
flag asserted.
rd_data_b_n[]
Yes
Out
Port b data bus
for FIFO n
One per FIFO. Behavior depends on mode of
read_b_n
signal.
read_b_n
Yes
In
Read request/
acknowledge
signal for
FIFO n
One per FIFO. The user is restricted from
asserting the
rd_en_b_n
for a FIFO whose
rd_empty_n
flag asserted. When
read_b_n
port is configured as a read acknowledge signal,
data is made available before
read_b_n
signal
is asserted, and asserting
read_b_n
signals to
the FIFO to output the contents of the next
location in the FIFO. When
read_b_n
is
configured as a read request, data becomes
available immediately after asserting
read_b_n
.
wr_full_n
Yes
Out
Port a full flag
for FIFO n
The write side FIFO full flag. This flag is
synchronous to the write port clock. The user is
restricted from asserting
wr_en_a_n
while
wr_full_n
is asserted. This flag may be
asserted for one or two clock cycles when the
FIFO is not full. To determine when the FIFO is
truly full, the user should examine this flag in
combination with the
wr_level_n
flag.
wr_empty_n
Yes
Out
Port a empty
flag for FIFO n
The write side FIFO empty flag. This flag is
synchronous to the individual write port clocks.
wr_level_n[]
No
Out
Port a level flag
for FIFO n
The write side FIFO level bus. Indicates how
many words are currently in the FIFO. These
status bits are synchronous to the write port
clocks. For FIFOs with a depth equal to a power
of two (i.e. 8, 16, 32, …), the
wr_full_n
flag is
considered the most significant bit of
wr_level_n
when
wr_level_n
= 0. This
status bus has one cycle of latency.
Table 3. FIFO Partitioner Port Listing (Part 2 of 3)
Port Name
Required Direction
Direction
Comments