i)At what ROM location do we store the first opcode of an 8051 program?
ans 000H
ii) Explain the CJNC and JB instruction with eg.
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a. Write the instructions to move value 34H into register A and value 3FH into register B, then add them together.
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c. What is the difference between semaphore and mutex?
refer book
a) Write a program to perform the following
i) Keep monitoring the P1.2 bit until it becomes high.
ii) When P1.2 becomes high, write value 45H to port 0 and
iii) Send a high-to-low(H-to-L) pulse to P2.3
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b) Explain addressing modes used in 8051.
Refer book
Explain the various task scheduling algorithms.
i) State the contents of memory locations 200H – 205H for the following
ORG 200H
MYDATA: DB “ABC123”
Ans 200H - “A” , 201H- “B”, 202H- “C”, 203H- “1”, 204H- “2”, 205H-”3”
ii) Find the CY and AC flag bits for the following code
MOV A,#0FFH
ADD A,#01
answer MOV A, #00, ADD A, #0FFh
CY=0
b. Explain Assembler directives of the 8051.
c. Explain different states of a task.
a) Explain the following instructions
i) DA ii) CJNC iii) CPL
b) Write a program to transfer the message “YES” serially at 9600 baud, 8-bit data,
1 stop bit. Do this continuously.
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c) Explain the use of message queues, mailboxes and pipes.
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