Digital Electronics - The 8051 Microcontroller - Discussion
Discussion Forum : The 8051 Microcontroller - General Questions (Q.No. 11)
11.
The following program will receive data from port 1, determine whether bit 2 is high, and then send the number FFH to port 3:
READ: MOV A,P1
ANL A,#2H
CJNE A,#02H,READ
MOV P3,#FFH
READ: MOV A,P1
ANL A,#2H
CJNE A,#02H,READ
MOV P3,#FFH
Discussion:
16 comments Page 2 of 2.
Ruben said:
1 decade ago
Line1. A = P1 'Read P1 then save in Acc.
Line2. A = A and 00000010 'And Operation.
Line3. If A <> 00000010 Goto Line1 'Compare.
Line4 Else P3 = #0ffh 'Send ffh to port 3.
Line2. A = A and 00000010 'And Operation.
Line3. If A <> 00000010 Goto Line1 'Compare.
Line4 Else P3 = #0ffh 'Send ffh to port 3.
Khyati said:
1 decade ago
In the operand of CJNE, there is a address or data? please reply.
Yash said:
1 decade ago
@Imtiyaz, they have asked to check the 2nd lsb i.e 2nd bit right why you want to know the whole digit.
Imtiyaz said:
1 decade ago
Contents of Port1 should be mentioned clearly, so that we can perform or take decision on CJNE instruction rite !
Manish gundev said:
1 decade ago
Thanks abhi.
Abhi said:
1 decade ago
1st : Copied to accumulator
2nd :ANDing operation
3rd : Compare jump if not equal
its always not equal
4th : Copied to port3 instruction
2nd :ANDing operation
3rd : Compare jump if not equal
its always not equal
4th : Copied to port3 instruction
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers