• ACC and B registers – 8 bit each
• DPTR : [DPH:DPL] – 16 bit combined
• PC : Program Counter – 16 bits
• Stack pointer SP – 8 bit
• PSW : Program Status Word
• Port Latches
• Serial data buffer, serial control
• Timer Registers (TCON,TMOD,TL0/1,TH0/1)
• Power control
• Interrupt Enable, Interrupt Priority