2. The state of a 12-bit register is 100010010111. What is its content if it represents (a) Three decimal digits in BCD? [1 mark] (b) Three decimal digits in the excess-3 code? [1 mark] (c) Three decimal digits in the 84-2-1 code? [1 mark] (d) A binary number?

(a) Three decimal digits in BCD: BCD stands for Binary Coded Decimal. It is a class of binary encodings of decimal numbers where each decimal digit is represented by a fixed number of bits, usually four. In this case, the 12-bit register can be divided into three 4-bit BCD codes.

1000 1001 0111

This represents the decimal numbers 8, 9, and 7.

(b) Three decimal digits in the excess-3 code: Excess-3 is a non-weighted code used to express decimal numbers. The code derives its name from the fact that each binary code is the corresponding 8421 BCD code plus 0011 (3).

1000 1001 0111

Subtracting 3 from each gives us 0101, 0110, 0100 which represent the decimal numbers 5, 6, and 4.

(c) Three decimal digits in the 8421 code: The 8421 code is another name for BCD (Binary Coded Decimal). So, the process is the same as in part (a).

1000 1001 0111

This represents the decimal numbers 8, 9, and 7.

(d) A binary number: If the 12-bit register represents a binary number, then we simply convert the binary number to decimal.

100010010111

This binary number converts to the decimal number 2239.