This improvement will solve a couple of [DRC REQP-1839] warning:
"The RAMB36E1 has an input control pin * which is driven by a register * that has
an active asynchronous set or reset. This may cause corruption of the memory
contents and/or read values when the set/reset is asserted and is not analyzed
by the default static timing analysis. It is suggested to eliminate the use of
a set/reset to registers driving this RAMB pin or else use a synchronous reset
in which the assertion of the reset is timed by default."
dma_raddr is only incremented if it is less than dma_waddr_rel_s.
dma_waddr_rel_s is always less or equal to adc_waddr_rel << RATIO and
adc_waddr_rel is less than DMA_ADDR_LIMIT >> RATIO.
By induction we can conclude that this means that dma_raddr will always be
less then DMA_ADDR_LIMIT and the check for this will always evaluate to
false can be removed.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
When the DMA clock to ADC data rate ratio exceeds a certain threshold it is
possible that an erroneous dma_waddr_rel toggle event is generated. This
causes the last address of the previous DMA transfer to be transferred to
the DMA domain. And the DMA side will start reading from the FIFO even
though data is not available yet.
This results in data corruption with the current transfer containing data
from the previous transfer.
The root cause here is that the toggle signal CDC synchronizer register are
reset in the DMA when a new transfer starts, but not in the ADC domain,
causing a potential mismatch and the incorrect toggle event. To fix this
remove the reset from the DMA side. This is OK since the registers are
self-resetting if the reset signal is asserted for more than 3 clock cycles.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The width of a ternary operator expression is the width of the wider of the
two selectable expression. This means depending on the selected DMA_RATIO
the right side expression of the dma_waddr_rel_s assignment can be up to
three bits wider than the dma_waddr_rel_s signal. This generates an
implicit truncation warning.
Slightly reformulate the expression without the use of the ternary operator
to avoid this warning.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
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
Add .gitattributes file which sets up the eol encoding handling. This will
make sure that we get a uniform eol encoding across different operating
systems.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Istvan Csomortani
Lars-Peter Clausen
Rejeesh Kutty
Adrian Costina