Logic shift left

Problem 1. (22 points) Short questions. 1. Which of the following choice(s) is/are correct? A penalty will be applied for every wrong answer. (a) (4 pts) All sequential circuits can be implemented using only JK flip-flops and NOT gates only T flip-flops and NAND gates only D flip-flops and AND gates only D flip-flops and NAND gates (b) (4 pts) An overflow can occur after the subtraction of two signed numbers the addition of two unsigned numbers a logic shift left an arithmetic shift right 2. Perform the following conversions. (a) (2 pts) (AB.2AD)16 = ( 171.1672 )10 (b) (2 pts) (10010.0)2 = ( 20 ) 9 3. A digital computer represents its floating point numbers using a signed 6-bit exponent and a signed normalized 10-bit mantissa. Negative exponent and mantissa values are expressed in 2's complement. Show the binary values of the exponent and mantissa to represent (21.1)8. 10-bit mantissa= - ---'0100010010----- 6-bit exponent= _..00101 4. Using Table 6, translate the following machine codes to their equivalent assembly instructions. Machine code (in Hex.) Equivalent in assembly ecce BUN CCC I 1234 ADD 234 DCBA BSA CBA I 7002 SZE lOM oARc PSD|7278690 Problem 2. (20 points) A JK flip-flop A is used by a CPU to perform the following micro-operations (in RTL): xT1 :A 0 Reset A to 0 yT2: A 1 Set A to 1 vT3: A 1 Set A to 1 Otherwise the content of A remains the same. The signals T1 , T2, ... are outputs of a decoder. 1. Draw the logic diagram of the control circuit governing the flip-flop A. 2. The above micro-operations are replaced by the following ones: Without using excitation tables and K-maps, draw the new logic diagram of the control circuit governing the flip-flop A. Problem 3. (26 points) Consider Program 1. 1. Use Table 6 to translate Program 1 in its equivalent machine code by specifying the machine code of each instruction/operand (in hexadecimal), and its address in the memory (in hexadecimal) Program 1: Assembly program ORG 0 X, HEX 0 ORG 17 Y, LDA A SZA LDA B INC STA C HLT ORG 100 A, 0 B, DEC 14 C, HEX 000A END I Address in Hex I Content in Hex I 2. After the execution of the program, what is the content (in hexadecimal) of the word with the symbolic address C? 0001 3. After the execution of the program, what is the content (in hexadecimal) of the register AC? AC = 0001 4. After the execution of the program, what is the content (in hexadecimal) of the word with addresszero? M[0] = 0000 0000 0000 0017 2100 0018 7004 0019 2101 001A 7020 001B 3102 001C 7001 0100 0000 0101 OOOE 0102 OOOA lOM oARc PSD|7278690 Problem 4. (20 points) SRT, 0 Solution: IDA 160 CIR ORG 50 SZE CLA BUN EXT STA 161 LDA 161 LOP, LDA PTR I INC STA 160 STA 161 BSA SRT EXT, BUN SRT l ISZ PTR ISZ CTR BUN LOP HLT PTR, 100 CTR, FFFO /DEC -16 Problem 5. (36 points) Consider the computer of Lab 3, the architecture of which is described in Figure 1 and Tables 1, 2, 3, 4, and 5. The instruction type is determined by the 2 most significant bits of the 8- bit register IR, as follows: • Xo = IR’(7) IR’(6) denotes a memory-referenced instruction (MRI) in direct addressing mode; • X1 = IR’(7) IR(6) denotes a register-referenced instruction (RRI); and • X2 = IR(7) IR’(6) denotes a memory-referenced instruction (MRI) in indirect addressing mode. The flip-flop S is a STOP register which prevents PC from being incremented if S = 1. Assume that all registers are equipped with 3 control bits for loading the register, increment it by 1, and reset it to zero. 1. Find the list of all the micro-operations which use the bus and group them according to the register to be placed on the bus (IR, AR, PC, etc.) 2. Draw the logic diagram of the control circuit which governs the bus. 3. Find the list of all the micro-operation which change: the value of register PC. " 4. Draw the logic diagram of the control circuit of PC.