The CIC filter introduces different amplifications depending on the
interpolation ratio. By adding a multiplier in the interpolation chain
the amplification can be compensated
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
The axi_dac_interpolate does not use the full width of the AXI interface
address. It only responds to register access in the first 32 registers.
Reduce the size of the AXI address to 7 bit accordingly. This allows the
scripts to correctly infer the internal register map size which will cause
the interconnect to filter out access to these unused register.
This slightly reduces utilization by getting rid of some pipeline
registers.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The output data mux is used to bypass the filter when it is not used. Which
setting is used for the mux depends on the 3-bit filter_mask signal.
Registering the control logic into a single bit signal reduces the amount
of routing resources required. Since changing the filter_mask settings is
asynchronous to the processing anyway the extra clock cycle delay
introduced by this change does not affect behaviour.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Move the processing pipeline of the axi_adc_decimate core to its own
sub-module. This makes it easier to simulate the processing independent of
the register map.
Also since the filter is two instances of the same logic, one for each
channel, let the new sub-module model one channel and instantiate it twice.
This allows to change the implementation without having to change the same
code twice.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
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.