2. The following figure illustrates a counter. Please answer the following questions. (a) If this is a mod-N counter, what is the value of N? (3%) (b) Is this counter up counting or down counting? (3%) (c) Please list the counting sequence (note: just list the initial and final states; for exam mod-5 counter). (6%) U3 U4 5V DCD HEX U1 CLK 74190N U2 MAX/MIN CLK 74190N NAND4 Fig. l: a mod-N counter. 2. The following figure illustrates a counter. Please answer the following questions. (a) If this is a mod-N counter, what is the value of N? (3%) (b) Is this counter up counting or down counting? (3%) (c) Please list the counting sequence (note: just list the initial and final states; for exam mod-5 counter). (6%) U3 U4 5V DCD HEX U1 CLK 74190N U2 MAX/MIN CLK 74190N NAND4 Fig. l: a mod-N counter