Tiêu đề 22421-2019-Winter-model-answer-paper.pdf ✅

MAHARASHTRA STATE BOARAD OF TECHNICAL EDUCATIOD (Autonomous) (ISO/IEC-27001-2005 Certified) WINTER– 2019 Examinations Subject Code: 22421 Model Answer Page 2 of 15 1 mark for Truth table and 1 for diagram T flip-flop input Present State Next State T Qt Qt+1 0 0 0 0 1 1 1 0 1 1 1 0 d) Implement following Boolean equation using fundamental gates :Y=ABC+A B C+ A C B Ans: 2 marks for correct diagram e) Identify direct addressing instructions from following instructions : (i) MOV RO, R5 (ii) MOV RO, 80 H (iii) MOV RO, #75H (iv) ADD A, 45 H Ans: Instructions ii) and iv) are direct addressing as 80H and 45H are direct addresses 2marks f) If initial content of accumulator is 44 H, find out the new content of accumulator after execution of the instruction RR A Ans: Contents of Acc will be 22H ( as RR A divides acc by 2) 2 marks g) Find out number of data lines required to interface 16 LEDs arrange in the 4 x 4 matrix form. Ans: 4+4=8, eight lines are required for 4x4 matrix of 16 LEDs 2 marks Q. 2 Attempt any THREE of the following 12 Marks a) Define following terms related to logic families : (i) Noise Margin (ii) FAN-OUT (iii) Propagation delay (iv) Power dissipation Ans: 1 marks for each definition i) Noise immunity is measured in terms of noise margin. High state Noise margin = VNH = VOH(min) - VIH(min) Low state Noise margin = VNL = VIL(max) - VOL(max)

MAHARASHTRA STATE BOARAD OF TECHNICAL EDUCATIOD (Autonomous) (ISO/IEC-27001-2005 Certified) WINTER– 2019 Examinations Subject Code: 22421 Model Answer Page 4 of 15 Q.3 Attempt any THREE of the following 12 Marks a) List out any four assembler directives and state their functions. Ans: 1 marks for each directive ORG directive: It is used to specify starting address of the Program. A 16bit address follows ORG ORG 0020H will start program from 0020H memory location. END directive: It indicates end of the assembly language program DB directive: he DB directive is the most widely used data directive in the assembler. It is used to define the 8-bit data. When DB is used to define data, the numbers can be in decimal, binary, hex, or ASCII formats. EQU directive: This is used to define a constant without occupying a memory location. The EQU directive does not set aside storage for a data item but associates a constant value with a data label so that when the label appears in the program, itp constant value will be substituted for the label. b) Sketch diagram showing interfacing of two chips of RAM having size 2k x 8 to 8051 microcontroller. Write its memory map. Ans: