Out of Context constraints are needed for timing driven synthesis as for
avoiding critical warnings due clock queries.
The memory from the FIFO is inferred in different ways for high clock
speeds. Assume the highest frequency for all projects.
The write logic (DMA side) has to be independent from the read logic (DAC side).
In general the FIFO is always ready for the DMA, and every DMA transaction will
interrupt the read-back process, and the module will stop sending data,
until the initialization is finished.
Bringing back the write address tot he DMA clock domain is totally
redundant, so delete it.
The DMAC implementation guarantees that the expression `dma_valid &
dma_xfer_req` is always identical to just dma_valid.
When generating the util_dacfifo dma_wren_s signal the optimizer doesn't know
of this though and hence will route both signals into the LUT that drives
the write enable for the BRAMs.
Simplify the expression by removing dma_xfer_req from it. Considering this
can be a fairly high fan-out net and is typically the bottleneck for the
util_dacfifo timing this helps to improve the timing.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Fix the following warnings that are generated by Quartus:
Warning (10236): Verilog HDL Implicit Net warning at util_dacfifo.v(257): created implicit net for "dac_mem_ren_s"
Warning (10230): Verilog HDL assignment warning at util_dacfifo.v(166): truncated value with size 32 to match size of target (10)
Warning (10230): Verilog HDL assignment warning at util_dacfifo.v(266): truncated value with size 32 to match size of target (10)
Warning (10230): Verilog HDL assignment warning at util_dacfifo.v(268): truncated value with size 32 to match size of target (10)
No functional changes.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Currently the individual IP core dependencies are tracked inside the
library Makefile for Xilinx IPs and the project Makefiles only reference
the IP cores.
For Altera on the other hand the individual dependencies are tracked inside
the project Makefile. This leads to a lot of duplicated lists and also
means that the project Makefiles need to be regenerated when one of the IP
cores changes their files.
Change the Altera projects to a similar scheme than the Xilinx projects.
The projects themselves only reference the library as a whole as their
dependency while the library Makefile references the individual source
dependencies.
Since on Altera there is no target that has to be generated create a dummy
target called ".timestamp_altera" who's only purpose is to have a timestamp
that is greater or equal to the timestamp of all of the IP core files. This
means the project Makefile can have a dependency on this file and make sure
that the project will be rebuild if any of the files in the library
changes.
This patch contains quite a bit of churn, but hopefully it reduces the
amount of churn in the future when modifying Altera IP cores.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
This reduces the amount of boilerplate code that is present in these
Makefiles by a lot.
It also makes it possible to update the Makefile rules in future without
having to re-generate all the Makefiles.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
In cases when a shallow FIFO is requested the synthesizer infers distributed RAM
instead of block RAMs. This can be an issue when the clocks of the FIFO are
asynchronous since a timing path is created though the LUTs which implement the
memory, resulting in timing failures. Ignoring timing through the path is not a
solution since would lead to metastability.
This does not happens with block RAMs.
The solution is to use the ad_mem (block RAM) in case of async clocks and letting
the synthesizer do it's job in case of sync clocks for optimal resource utilization.
The grey coder/decoder function was limited to 10 bits, and this
resulted an unwanted limitation of the FIFO size. Using this
module, the coder/decoder data width can be adjusted to the current
address width.
All the hdl (verilog and vhdl) source files were updated. If a file did not
have any license, it was added into it. Files, which were generated by
a tool (like Matlab) or were took over from other source (like opencores.org),
were unchanged.
New license looks as follows:
Copyright 2014 - 2017 (c) Analog Devices, Inc. All rights reserved.
Each core or library found in this collection may have its own licensing terms.
The user should keep this in in mind while exploring these cores.
Redistribution and use in source and binary forms,
with or without modification of this file, are permitted under the terms of either
(at the option of the user):
1. The GNU General Public License version 2 as published by the
Free Software Foundation, which can be found in the top level directory, or at:
https://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html
OR
2. An ADI specific BSD license as noted in the top level directory, or on-line at:
https://github.com/analogdevicesinc/hdl/blob/dev/LICENSE
Xilinx recommends that all synchronizer flip-flops have
their ASYNC_REG property set to true in order to preserve the
synchronizer cells through any logic optimization during synthesis
and implementation.
Update the way how the fifo push out its content. By default the fifo pushes out all its content, if an xfer_last signal is received, the fifo saves the last write address, and reads out until the saved address.
stefan.raus
Istvan Csomortani
Laszlo Nagy
Lars-Peter Clausen
Adrian Costina
Rejeesh Kutty