Question 1. In a typical keypad switch, bouncing occurs for how long?

5 to 20 ns

5 to 20 μs

5 to 20 ms

5 to 20 s

Question 2. The following data will display the letter ‘A' on the LCD.

data = 0x41, CSB = 0, E = ↓, RS = 1, R/W~ = 0

data = 0x61, CSB = 0, E = ↓, RS = 1, R/W~ = 0

data = 0x41, CSB = 0, E = ↓, RS = 0, R/W~ = 0

data = 0x61, CSB = 0, E = ↑, RS = 1, R/W~ = 0

Question 3. For the LCD, describe the function accomplished with the RS control signal. Also, indicate whether this signal is an LCD input or LCD output.

Question 4. Describe how the 74C922 IC operates and its interface between the keypad and the microcontroller.

Question 5. In the LCD initialization sequence, which command configures the LCD to a 4-bit data transfer instead of an 8-bit data transfer? Also, identify the point in the initialization sequence that this occurs.