If I understand what you are asking, such a function will almost certainly require hardware support at a very low level (for example, a counter that monitors memory bus activity). I don’t think that such support is available for general architectures supported by Unix or Linux, so I’m going to go limp and say that such a Unix command does not exist.
The situation is somewhat different when considering memory in units of pages, because most architectures that support virtual memory have dedicated MMU equipment that works at this level of detail, and they can be accessed by the system. But, as far as I know, the types of counter data that you received from the MMU represent events, such as page errors, distributions and releases, rather than individual reads or writes.