A command decoder used for a microcontroller based Flash memory digital
controller system includes multiple subsystems, including the command
decoder, which serves as the main user interface for interpreting
commands from a user and managing the priority of commands and command
modes. The command decoder also stores crucial information including
address, data, opcodes, and various flags registers that are used by
other subsystems including the program buffer, burst read module,
register block, and microcontroller. In addition, the command decoder
contains clock synchronization logic, controls the sleep function of the
microcontroller and serves as a test mode controller.