For a proper reset synchronization, the asynchronous reset signal should
be connected to the reset pins of the two synchronizer flop, and the
data input of the first flop should be connected to VCC.
In the first stage we're synchronizing just the reset de-assertion, avoiding
the scenario when different parts of the design are reseting at different time,
causing unwanted behaviours.
In the second stage we're synchronizing the reset assertion.
The module expects an ACTIVE_HIGH input reset signal, and provides an ACTIVE_LOW
(rstn) and an ACTIVE_HIGH (rst) synchronized reset output signal.
The DC filter implementation in library/common/dc_filter.v is Xilinx
specific as it uses the Xilinx DSP48 hard-macro. There is a matching Altera
specific implementation in library/altera/common/dc_filter.v.
Move the Xilinx specific implementation from the generic common folder to
the Xilinx specific common folder in library/xilinx/common/ since that is
where all other Xilinx specific common modules reside.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The up_rstn is driven by s_axi_resetn, which is generated by a
Processor System Reset module. (connected to port peripheral_aresetn)
Therefor using this reset signal as an asynchronous reset is redundant,
and a bad design practice at the same time. Asynchronous reset should be
used if it's inevitable.
Currently the clock monitor features a hold register in the monitored clock
domain. This old register is used to store a instantaneous copy of the
counter register. The value in the old register is then transferred to the
monitoring domain. Since the counter is continuously counting it is not
possible to directly transfer it since that might result in inconsistent
data.
Instead stop the counter and hold the registers stable for a duration that
is long enough for the monitoring domain to correctly capture the value.
Once the value has been transferred the counter is reset and restarted for
the next iteration.
This allows to eliminate the hold register, which slightly reduces
utilization.
The externally visible behaviour is identical before and after the patch.
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
Can not be multiple 'if' statements inside a generate block. If there are
multiple cases use if/esle statement, but always should be one single
if/else inside a generate.
Currently the IDDRs are configured in SAME_EDGE_PIPELINED mode, but then
the negative data is delayed by an additional clock cycle. This is the same
behaviour as using the IDDR in SAME_EDGE mode.
Switching to SAME_EDGE mode removes extra pipelining registers while
maintaining the same behaviour.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
In modules ad_serdes_in/ad_serdes_out the handover of the parameter
SERDES_FACTOR did not exist, causing unwanted behavioral in case of
factors less than 8.
SERDES_FACTOR must be hand over to DATA_WIDTH parameter of the SERDES
primitive.
Istvan Csomortani
AndreiGrozav
Lars-Peter Clausen
Rejeesh Kutty
Adrian Costina
Istvan Csomortani