The MSB of the d_count signal is used as a overflow marker to stop the
counter from incrementing in the monitored clock domain. It is not exported
through the register map and truncated when assigned to the up_d_count
signal.
Make the truncation explicit to make it clear that this is not a mistake
and to avoid warnings about implicit truncation.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
All verilog file are using the Verilog-2001 standard to define
and/or declare ports. Definin a port width with a local parameter
is a bad practive, when this standard is used. Some simulators
will crash. Try to avoid it.
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>
The clock monitor reports the ratio of the clock frequencies of a known
reference clock and a monitored unknown clock. The frequency ratio is
reported in a 16.16 fixed-point format.
This means that it is possible to detect clocks that are 65535 times faster
than the reference clock. For a reference clock of 100 MHz that is 6.5 THz
and even if the reference clock is running at only 1 MHz it is still 65
GHz, a clock rate much faster than what we'd ever expect in a FPGA.
Add a configuration option to the clock monitor that allows to reduce the
number of integer bits of ratio. This allows to reduce the utilization
while still being able to cover all realistic clock frequencies.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Currently when the monitored clock stops the clock monitor retains the old
frequency ratio value and there is no way to detect that the clock has
stopped and the reported value is indistinguishable form a clock still
running at the right rate.
If a full iteration as elapsed on the monitoring side and there is no
indication that the counter on the monitored side has started running set
the reported clock ratio value to 0 to indicate that the clock has stopped.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
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
In case of high precision devices with just a simple SPI interface
for control and data, the effective data rate can be significatly
lower than the SPI clock, and more importantly there isn't any relation
between the two clock domain.
The rate is defined by a SOT (start of transfer) generator, which
initiates a SPI transfer. Taking the fact that the generator runs
on system clock (100 MHz), and the device can require smaller rate (in kHz domain),
the 7 bit dac_datarate register is just too small.
Therefor increasing to 16 bit.
Not all peripherals need the full address space. To be able to infer the
size of the address space of a peripheral allow the size of the AXI address
signals to be configurable rather than hardcoding its width to 32 bit.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Not all peripherals use the GPIO register settings, but the registers still
take up a fair amount of space in the register map. Add options to allow to
disable them when not needed. This helps to reduce the utilization for
peripherals where these features are not needed.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Not all peripherals use the GPIO and START_CODE register settings, but the
registers still take up a fair amount of space in the register map. Add
options to allow to disable them when not needed. This helps to reduce the
utilization for peripherals where these features are not needed.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
For experimentation, to solve a constraint scoping issue, split up the
ad_axi_ip_constraint file into separate constraints file, in function
of there parent module.
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.
The SYSREF generator is using a simple free running counter,
which runs on the JESD204 core clock. The period can be
configured using a parameter, it must respect the constraints
defined by the JESD204 standard.
The generator can be enabled through a GPIO line.
The axi_jesd_gt was repleaced by axi_adxcvr IP, which is located
at library/xilinx and library/altera.
The axi_jesd_xcvr was an early version of axi_adxcvr.
The register map is moved to the IP's directory.
Rejeesh Kutty
Lars-Peter Clausen
Istvan Csomortani
Adrian Costina
Istvan Csomortani