Part of the latency from memory read or write operations is for data to be
input to or output from the data latches of the memory via an I/O bus.
Methods and circuitry are present for improving performance in
non-volatile memory devices by allowing the memory to perform some of
these data caching and transfer operations in the background while the
memory core is busy with a read operation. A read caching scheme is
implemented for memory cells where more than one bit is sensed together,
such as sensing all of the n bits of each memory cell of a physical page
together. The n-bit physical page of memory cells sensed correspond to n
logical binary pages, one for each of the n-bits. Each of the binary
logical pages is being output in each cycle, while the multi-bit sensing
of the physical page is performed every nth cycles.