The util_cpack2 core is similar to the util_upack core. It packs, or
interleaves, a data from multiple ports into a single data. Ports can
optionally be enabled or disabled.
On the input side the cpack2 core uses a multi-port FIFO interface. There
is a single data write signal (fifo_wr_en) for all ports. But each port can
be individually enabled or disabled using the enable signals.
On the output side the cpack2 core uses a single port FIFO interface. When
data is available on the output interface the data write signal
(packed_fifo_wr_en). Data on the packed_fifo_wr_data signal is only valid
when packed_fifo_wr_en is asserted. At other times the content is
undefined. The cpack2 core offers no back-pressure. If data is not consumed
when it is made available it will be lost.
Data from the input ports is accumulated inside the cpack2 core and if
enough data is available to produce a full output vector the data is
forwarded.
This core is build using the common pack infrastructure. The core that is
specific to the cpack2 core is mainly only responsible for generating the
control signals for the external interfaces.
The core is accompanied by a test bench that verifies correct behavior for
all possible combinations of enable masks.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The util_upack2 core is similar to the util_upack core. It unpacks, or
deinterleaves, a data stream onto multiple ports.
The upack2 core uses a streaming AXI interface for its data source instead
of a FIFO interface like the upack core uses.
On the output side the upack2 core uses a multi-port FIFO interface. There
is a single data request signal (fifo_rd_en) for all ports. But each port
can be individually enabled or disabled using the enable signals.
This modified architecture allows the upack2 core to better generate the
valid and underflow control signals to indicate whether data is available
in a response to a data request.
If fifo_rd_en is asserted and data is available the fifo_rd_valid signal
are asserted in the following clock cycle. The enabled fifo_rd_data ports
will be contain valid data during the same clock cycle as fifo_rd_valid is
asserted. During other clock cycles the output data is undefined. On
disabled ports the data is always undefined.
If no data is available instead the fifo_rd_underflow signal is asserted in
the following clock cycle and the output of all fifo_rd_data ports is
undefined.
This core is build using the common pack infrastructure. The core that is
specific to the upack2 core is mainly only responsible for generating the
control signals for the external interfaces.
The core is accompanied by a test bench that verifies correct behavior for
all possible combinations of enable masks.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Pack and unpack operations are very similar in structure as such it makes
sense for pack and unpack core to share a common infrastructure.
The infrastructure introduced in this patch is based on a routing network
which can implement the pack and unpack operations and grows with a
complexity of N * log(N) where N is the number of channels times the number
of samples per channel that are process in parallel.
The network is constructed from a set of similar stages composed of either
2x2 or 4x4 switches. Control signals for the switches are fully registered
and are generated one cycle in advance.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Lars-Peter Clausen