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.
This core can be used in conjunction with the SPI_ENGINE, will work
as an offload module, forwarding a data stream to the SPI excecution,
received from a DMA.
It seems that there are some dependencies between the fir compiler
cores parameters. With the old order of the parameter settings,
the tool throws the following warning:
CRITICAL WARNING: [BD 41-237] Bus Interface property TDATA_NUM_BYTES
does not match between /processing/sequencer/i_q_filtered(4)
and /processing/lpf/M_AXIS_DATA(5)
Depending on the configuration of the clock source type of the input clock
the clocking wizard will instantiate all kinds of buffers on the input
clock signal.
For these particular projects there is no need to add any kind of buffer
since the source is already coming from a global clock buffer. So set the
configuration accordingly.
Avoids the following warning:
[Opt 31-32] Removing redundant IBUF since it is not being driven by a
top-level port. i_system_wrapper/system_i/sys_audio_clkgen/inst/clkin1_ibufg
Resolution: The tool has removed redundant IBUF. To resolve this
warning, check for redundant IBUF in the input design.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
There is no need for the audio clock to be phase aligned to its source
clock. When phase alignment is disabled the MMCM uses an internal feedback
path without requiring external resources, so disable it.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Instead of manually specifying the input clock frequency let the core infer
it automatically. This makes it more straight forward to change the clock
frequency.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Neither the reset nor the locked signal is used in this design, so disable them. Avoids warnings about unconnected pins.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Istvan Csomortani
Rejeesh Kutty
Adrian Costina
Lars-Peter Clausen