Matches NumPy. Slicing a TList reallocates, this doesn't; offsetting
couldn't be handled in the IR without introducing new semantics
(the Alloc kludge; could/should be made its own IR type).
Still needs support through all the rest of the compiler, and
support for higher-dimensional arrays.
Alternatively, we could always assume ndarrays of ndarrays
are rectangular (i.e. ban array/list element types), and
detect mismatch at runtime. This might turn out to be
preferrable to be able to construct matrices from rows/columns.
`array()` is disallowed for no particularly good reason but
numpy API compatibility.
* coredevice.ad9910: Add return type hints to conversion functions
* coredevice.ad9910: Make set_pow write correct number of bits
The AD9910 expects 16 bits. Thus, if writing 32 bits to the POW register, the chip would likely enter a locked-up state.
* coredevice.ad9910: Correct data alignment in write_16
Co-authored-by: Robert Jördens <rj@quartiq.de>
* coredevice.ad9910: Add function to read from 16 bit registers
Co-authored-by: drmota <peter.drmota@physics.ox.ac.uk>
Co-authored-by: Robert Jördens <rj@quartiq.de>
This reverts commits f8d1506922
and cf19c9512d.
While the commit just fixes a clear typo in the implementation,
it turns out the original algorithm isn't flexible enough to
capture functions that transitively return references to
long-lived data. For instance, while cache_get() is special-cased
in the compiler to be recognised as returning a value of Global()
lifetime, a function just forwarding to it (as seen in the
embedding tests) isn't anymore.
A separate issue is also that this makes implementing functions
that take lists and return references to global data in user code
impossible, which central parts of the Oxford codebase rely on.
Just reverting for now to unblock master; a fix is easily designed,
but needs testing.
I contemplated putting this in the "Breaking changes" section,
as it might break user code that has avoided being hit by
memory corruption from the use-after free by chance (even
though it was always an accepts-illegal bug).
* Never drive SDL or SDA high. They are specified to be open
collector/drain and pulled up by resistive pullups. Driving
high fails miserably in a multi-master topology (e.g. with
a USB I2C interface). It would only ever be implemented to
speed up the bus actively but that's tricky and completely
unnecessary here.
* Make the handover states between the I2C protocol phases (start, stop,
restart, write, read) well defined. Add comments stressing those
pre/postconditions.
* Add checks for SDA arbitration failures and stuck SCL.
* Remove wrong, misleading or redundant comments.
