This is about as simple as a microprocessor gets. This
microprocessor has:
• An address bus (that may be 8, 16 or 32 bits wide) that
sends an address to memory
• A data bus (that may be 8, 16 or 32 bits wide) that can
send data to memory or receive data from memory
• An RD (read) and WR (write) line to tell the memory
whether it wants to set or get the addressed location
• A clock line that lets a clock pulse sequence the
processor
• A reset line that resets the program counter to zero (or
whatever) and restarts execution
• Let's assume that both the address and data buses are
8 bits wide in this example