a) (10p) What does the following circuit do? Explain with numeric values. (Note: 74LS373: Octal D Latch, 74LS244: Octal 3-State Buffer) 74LS373 XD0 LEDs IOW XD7 G C AD A B A1 AZ Yib 74LS244 A3 Switches XDO Systems buffered XDT data bus A4 A5 AEN Y4D OC CC a d G28 A7 A8 A9 IOR Explanation: b) (6) According to the given circuitry, indicate the port addresses A, B, C and the control word 8255 DO D7 IOW WR IOR RD 0 A2 A1 A1 a cs A7 Port A: Port B: (2p) (1p) (Ip) Port C: Control Word: (3p) 3