NOTE !! You must answer them all OR leave them to another Instructor.

Be aware These multiple choices from class "8051 Microcontroller and Embedded Systems"

Give direct answers!

23. What is the final result in Port 1 after the execution of the following program segment MOV A, #55H CPL A MOV P1, A A. FFH B. 55H CJ AAH D. 00H 24. What are the contents of the P2 port after execution of the following program segment? MOV A, #8FH MOV P2, A SETB P2.5 A. A0H BJAFH C. OFH D. 2FH 25. What are the contents of the P1 port after execution of the following program segment? MOV A, #55H MOV P1, A SETB P1.3 CLR P1.4 A. 6DH B. 4AH C. 55H D) 4DH 26. The job of the TMOD register is to A. control the transfer of modified data B. temporarily modify output data values c.set the timer operating mode D. generate time delay durations 27. Which of the following does not affect a timer delay written in an 8051 C program? A. Crystal frequency of 8051 system B. 8051 machine cycle timing C. TMOD setting D/C data type 28. When is the timer flag raised in the 8051 timer for Mode 1? A. When the value in the timing register changes from 00H to FFH B. When the value in the timing register changes from FFH to 00H C When the value in the timing register changes from FFFFH to 0000H D. When the value in the timing register changes from 0000H to FFFFH