For projects where the clock ratio between the sampling clock and core clock
is higher than 2, the ad_dds generates a number of samples equal with
the clock ratio. There is a phase offset between the samples, proportional
with the requested DDS frequency.
In scenarios where the DDS out frequency is closer to the upper
limit(Nyquist) and/or the clock ratio is also greater than 2 and the
dac_data_sync reminds low for an extended period of time, the DAC will
receive at each core clock period, a number of samples equal with the
clock ratio and with an amplitude influenced by the DDS out frequency.
In most cases similar with a sawtooth signal.
With this commit we ensures that samples received by the DAC are 0 for
the period where dac_data_sync signal is high. Only when the signal
transitions to low, the phase accumulator is initialized and the phase
information is passed to the phase to amplitude converter.
Another issue can appear when the sync signal is too short; less then
CLK_RATIO * clock cycles. Because the phase accumulator will not
synchronize at all stages, the final result will be a random combination of
sine-waves. Added a minimum sync pulse after the dac_data_sync is set
low.
The external synchronization signal should be synchronous with the
dac clock. Synchronization will be done on the rising edge of the signal.
The control bit is self clearing. Status bit shows that the synchronization
is armed but the synchronization signal has not yet been received
Added EXT_SYNC parameter to be able to keep the dac_sync original
behavior
The module can receive a synchronous or asynchronous pulse with an arbitrary
width and generate a SYNC signal for the DMA Source AXI Streaming interface.
This way we can synchronize the DMA transfers to an external
pulse/signal.
Move the subtraction outside of the always block. In this way we're not adding
an additional delay element on to the output of the differentiator,
which brakes the transfer function of the filter.
Common basic steps:
- Include/create infrastructure:
* Intel:
- require quartus::device package
- set_module_property VALIDATION_CALLBACK info_param_validate
* Xilinx
- add bd.tcl, containing init{} procedure. The init procedure will be
called when the IP will be instantiated into the block design.
- add to the xilinx_blockdiagram file group the bd.tcl and common_bd.tcl
- create GUI files
- add parameters in *_ip.tcl and *_hw.tcl (adi_add_auto_fpga_spec_params)
- add/propagate the info parameters through the IP verilog files
axi_clkgen
util_adxcvr
ad_ip_jesd204_tpl_adc
ad_ip_jesd204_tpl_dac
axi_ad5766
axi_ad6676
axi_ad9122
axi_ad9144
axi_ad9152
axi_ad9162
axi_ad9250
axi_ad9265
axi_ad9680
axi_ad9361
axi_ad9371
axi_adrv9009
axi_ad9739a
axi_ad9434
axi_ad9467
axi_ad9684
axi_ad9963
axi_ad9625
axi_ad9671
axi_hdmi_tx
axi_fmcadc5_sync
To prevent the case, when after an invalid configuration, the generated
output PWM signal is constant HIGH, change the counter to a
down-counter. In this way the pulse will be placed at the end of the
PWM period, and if the configured width value is higher than the
configured period the output signal will be constant LOW.
Write code to pipeline data path for better DSP utilization on the
color space conversion.
In the old method the addition operations were performed outside the
DSPs
For consistent simulation behavior it is recommended to annotate all source
files with a timescale. Add it to those where it is currently missing.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
The perfect shuffle is a common operation in data processing. Add a shared
module that implements this operation.
Having this in a shared module rather than open-coding every instance makes
sure that there are clear and well defined semantics associated with the
operation that are the same each time. This should ease review, maintenance and
understanding of the code.
The perfect shuffle splits the input vector into NUM_GROUPS groups and then
each group in WORDS_PER_GROUP. The output vector consists of
WORDS_PER_GROUP groups and each group has NUM_GROUPS words. The data is
remapped, so that the i-th word of the j-th word in the output vector is
the j-th word of the i-th group of the input vector.
The inverse operation of the perfect shuffle is the perfect shuffle with
both parameters swapped.
I.e. [perfect_suffle B A [perfect_shuffle A B data]] == data
Examples:
NUM_GROUPS = 2, WORDS_PER_GROUP = 4
[A B C D a b c d] => [A a B b C c D d]
NUM_GROUPS = 4, WORDS_PER_GROUP = 2
[A a B b C c D d] => [A B C D a b c d]
NUM_GROUPS = 3, WORDS_PER_GROUP = 2
[A B a b 1 2] => [A a 1 B b 2]
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
If DDS_DW is equal to DDS_D_DW there is no signal truncation and
consequentially no rounding should be performed. But the check whether
rounding should be performed currently is for if DDS_DW is less or equal to
DDS_D_DW.
When both are equal C_T_WIDTH is 0. This results in the expression
'{(C_T_WIDTH){dds_data_int[DDS_D_DW-1]}};' being a 0 width signal. This is
not legal Verilog, but both the Intel and Xilinx tools seem to accept it
nevertheless.
But the iverilog simulation tools generates the following error:
ad_dds_2.v:102: error: Concatenation repeat may not be zero in this context.
Xilinx Vivado also generates the following warning:
WARNING: [Synth 8-693] zero replication count - replication ignored [ad_dds_2.v:102]
Change the condition so that truncation is only performed when DDS_DW is
less than DDS_D_DW. This fixes both the error and the warning.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
This patch will fix the following critical warning, generated by Quartus:
"Critical Warning (18061): Ignored Power-Up Level option on the following
registers
Critical Warning (18010): Register ad_rst:i_core_rst_reg|rst_sync will power
up to High File: ad_rst.v Line: 50"
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.
Laszlo Nagy
AndreiGrozav
Adrian Costina
Istvan Csomortani
Arpadi
Edward Kigwana
Lars-Peter Clausen