CMSC 311- Computer Organization
Fall 1995 - Assignment #6
Due (at the beginning of class) Thursday, November 2
- Design a 4-bit register with the ability either to parallel
load, to (bitwise) AND its parallel inputs with its current state,
or to (bitwise) OR its parallel inputs with its current state.
Your register should have two inputs, S1 and S2, to control its
function. The function table for the register is given below:
S0 S1 Function
0 0 Do Nothing
0 1 Parallel load
1 0 Parallel AND
1 1 Parallel OR
- Design a circuit that performs a right circular shift of a
four bit number by an arbitrary number of bits. Your circuit should
have four input bits, four output bits and two control lines (S2,
S1) that indicate the number of bit positions the input should
be shifted (0, 1, 2, 3). The time to shift should not depend
of the number of bits positions being shifted.
- Design a combinational circuit that can compute any of the
first eight of the logic operations (F0 thru F7) from Table 4-5
in Mano (page 110). Your circuit should have data inputs x and
y, a single output z, and select inputs to determine which function
is to be computed (how many select inputs do you need?). Show
a circuit diagram.
- From Mano, problem 4-17.
- Given the initial state of Mano's computer shown below, trace
through its execution, and show the memory, PC, and AC after each
instruction has executed. Assume PC and AC are zero at the start.
From Mano, problem 5-1.
- From Mano, problem 5-4.