Memory access tests #356
Description
The documentation says some of our memory is writable only in words but readable in bytes. There are many variations.
The current tests in testfw and testapp are not covering every use case, so it would be good to make them more complete.
testfw and testapp are not machine readable, so perhaps it would make sense to make a new program, or rewrite them, to make them output something that can be used in CI?
The same programs can be used to check that the emulator at least emulates the correct access patterns.