The round function from tcl is a rounding to nearest. Using it in address
width calculation produces incorrect values.
e.g.
round(log(0xAF000000)/log(2)) will produce 31 instead of 32
The fix is to replace the rounding function with ceiling that guarantees
rounding up.
- remove reset logic
- add wait for dac valid logic
- rewrite sine concatenation on wires for different path width to
suppress warnings
- use computed atan LUT tables
The CORDIC has a selectable width range for phase and data of 8-24.
Regarding the width of phase and data, the wider they are the smaller
the precision loss when shifting but with the cost of more FPGA
utilization. The user must decide between precision and utilization.
The DDS_WD parameter is independent of CORDIC(CORDIC_DW) or
Polynomial(16bit), letting the user chose the output width.
Here we encounter two scenarios:
* DDS_DW < DDS data width - in this case, a fair rounding will be
implemented corresponding to the truncated bits
* DDS_DW > DDS data width - DDS out data left shift to get the
corresponding concatenation bits.
Update for the parametrized ad_mul module. This will scale
a selectable sine width in a multiplication module.
Rename the data and phase width parameters for legibility.
When the tool calculates the X value for different phase widths, we
get rounding errors for every width in the interval [8;24].
Depending on the width thess errors cause overflows or smaller amplitudes
of the sine waves.
The error is not linear nor proportional with the phase. To fix the issue
a simple aproximation was chosen.
Perform the shifting operation before addition/subtraction in a
rotation stage. In the previous method, the result of the arithmetic
operation was shifted and the outcome was presented to the next stage.
In this way, data connections will be reduced between pipeline stages
Add parameters:
- to select the sine generator (polynomial/CORDIC)
- to select the CORDIC data width(default 16)
Suppress the warnings generated when the DDS is disabled.
https://en.wikipedia.org/wiki/CORDIC
Configurable in/out data width (14,16,18,20);
The HDL implementation requires pipelines, resulting in a
data_width + 2 clock cycles delay between the phase input data and the
sine data. For this reason, a ddata (delay data) was propagated through
the pipeline stages to help in future use scenarios
Some FMC boards do utilize more than one transceiver quad but do not
necessarily use all transceivers in a quad. On such board is the
AD9694-500EBZ. Which uses two transceivers each in two adjacent quads.
This board can not be supported by instantiating a util_adxcvr with only 4
lanes. Since those 4 lanes would be packed into the same quad. Instead it
it is necessary to instantiate a util_adxcvr with 6 lanes. 4 lanes for the
first quad and 2 for the second.
To still to be able to connect such a util_adxcvr to a link layer with only
4 lanes allow to specify sparse lane mappings. A sparse mapping can have
less lanes than the util_adxcvr and some lanes will be left unconnected.
For example for the AD9694-500EBZ the lane mapping looks like the following:
ad_xcvrcon util_ad9694_xcvr axi_ad9694_xcvr ad9694_jesd {0 1 4 5} rx_device_clk
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Sometimes the output clock of the transceiver should not be used for the
device clock.
E.g. for deterministic latency with no uncertainty the device clock needs
to be sourced directly from a clock or transceiver reference clock input
pin.
Add an option to the ad_xcvrcon command to specify the device clock.
In case the same device clock is used for multiple JESD204 links, e.g. a TX
and a RX link only one reset generator is created.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Typically only one of the character error conditions is true at a time. And
even if multiple errors were present at the same time we'd only want to
count one error per character.
For each character track whether at least one of the monitored error
conditions is true. Then count the number of characters for which at least
one error condition occurred. And finally add that sum to the total numbers
of errors.
This results in a slightly better utilization.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
When the link is explicitly disabled through the control interface reset
the error statistics counter.
There is usually little benefit to preserving until after the link has been
disabled. If software is interested in the values it can read them before
disabling the link. Having them reset makes the behavior consistent with
all other internal state of the jesd204 RX peripheral, which is reset when
the link is disabled.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
In MM2S applications like video DMA it is useful to mark the end of the stream
with the TLAST.
The change enables the generation of the TLAST on the last beat of the
last row of the 2d transfer.
Laszlo Nagy
AndreiGrozav
Lars-Peter Clausen