What's inside the 8051:
  1. core, including the internal RAM (and ALU, memory controller, instruction decoder etc. - all this normally hidden to the user) - this is the part which executes the program (see SW model )
  2. program memory - if it is EPROM or FLASH, we can burn the program into it
  3. peripherals - core accesses them via SFRs:
    • timers/counters?
    • UART?
    • inputs/outputs? (IO)
    • interrupts?
  4. reset? logic
  5. clock? circuits (incl. oscillator)
  6. external memory? interface