The MAX_BYTES_PER_BURST option allows to configure the maximum bytes that
are part of a burst. This can be an arbitrary value.
At the same time there is a limit of how many bytes can be supported by the
memory buses. A AXI3 interface supports a maximum of 16 beats per burst
and a AXI4 interface supports a maximum of 256 beats per burst.
At the moment the it is possible to specify a MAX_BYTES_PER_BURST value
that exceeds what can be supported by the AXI memory-mapped bus. If that is
the case undefined behavior will occur and the DMAC will function
incorrectly.
To avoid this make sure that the MAX_BYTES_PER_BURST value does not exceed
the maximum that can be supported by the interfaces.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
When the DMAC is used in async clock domains the data FIFO instantiate
an ad_mem component to handle properly the clock crossing.
For Intel, this mode is used only in FMCJESDADC1 designs but without this
an error could appear in other projects too if the user reconfigures the core.
Exposed AXI3 interface on the Intel version of the IP for UI and feature consistency.
Some of the signals that are defined as optional in the AMBA standard
are marked as mandatory in Qsys in case of AXI3. Because of this such signals
were added to the interface of the DMAC and driven with default values.
For Xilinx in order to keep existing behavior the newly added signals
are hidden from the interface.
New parameters are added to define the width of the AXI transaction IDs;
these are hidden from the UI; We can add them to the UI if the fixed size
of the IDs will cause port incompatibility issues.
The primary use-case of the DMA controller is in non-2D mode. Make this the
default, since allows projects to instantiate the controller with the
default configuration without having to explicitly disable 2D support.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Currently the axi_dmac_hw.tcl script does not create interfaces if they
are not used in the current configuration. This has the disadvantage that
the ports belonging to these interfaces are not included in the generated
HDL wrapper. Which will generate a fair bunch of warnings when synthesizing
the HDL.
Instead always generate all interfaces, but disable those that are not used
in the current configuration. This will make sure that the ports belonging
to these interfaces are properly tied-off in the generate wrapper HDL.
This reduces the amount of false positive warnings generated and makes it
easier to spot actual issues.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The external s_axi_{awaddr,araddr} signals that are connect to the core
have their width set according to the specified size of the register map.
If the s_axi_{awaddr,araddr} signal of the core is wider (as it currently
is for many cores) the MSBs of those signals are left unconnected, which
generates a warning.
To avoid this make sure that the signal width matches the declared register
map size.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The axi_dmac can issue up to FIFO_SIZE read and write requests in parallel.
This is done in order to maximize throughput and compensate for for
latency.
Set the {read,write}IssuingCapability properties accordingly on the AXI
master interfaces. Otherwise qsys might decide to insert bridges that
artificially limit the number of requests, which in turn might affect
performance.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Qsys allows to query to query the clock domain that is associated with a
clock input of a peripheral. This allows to automatically detect whether
the different clocks of the DMAC are asynchronous and CDC logic needs to be
inserted or not.
Auto-detection has the advantages that the configuration parameters don't
need to be set manually and the optional configuration will be choose
automatically. There is also less chance of error of leaving the settings
in a wrong configuration when e.g. the clock domains change.
In case the auto-detection should ever fail configuration options that
provide a manual overwrite are added as well.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Group configuration parameters by function, provide human readable labels
as well as specify the allowed ranges for each parameter.
This prevents accidental misconfiguration and also makes it easier to
inspect (or change) the configuration in the Qsys GUI.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Use the ad_ip_intf_s_axi helper function to create the axi4lite slave
interface for memory mapped peripherals. This slightly reduces the amount
of boilerplate code in the peripheral's *hw.tcl
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The axi_dmac can issue up to FIFO_SIZE read and write requests in parallel.
This is done in order to maximize throughput and compensate for for
latency.
Set the {read,write}IssuingCapability properties accordingly on the AXI
master interfaces. Otherwise qsys might decide to insert bridges that
artificially limit the number of requests, which in turn might affect
performance.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Move the CDC helper modules to a dedicated helper modules. This makes it
possible to reference them without having to use file paths that go outside
of the referencing project's directory.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Bring back the AXIS FIFO as a separate module instead of embedding it into
the DMAC module. This makes it possible to use it in other modules outside
of the DMAC.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Move the axi_repack block to its own module. This allows it to use it
outside of the DMA controller.
Also rename it to util_axis_resize to better reflect its function.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
We can remove the Altera toplevel wrapper if we switch the axi4 control bus
to axi4lite and add the few missing signals that are required by the Altera
interconnect to both the control and the data buses.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>