MICROPROCESSOR AND MICROCONTROLLER

Detailed explanation-1: -8. To set the bits of a register R1 to 1, we must OR the contents of the register with? Explanation: To make the contents of the register R1 to 1 we must OR the contents of that register with FFH because according to Or algorithm 0+1=1 and 1+0=1.

Detailed explanation-2: -7. How are the bits of the register PSW affected if we select Bank2 of 8051? Explanation: Bits of PSW register are CY, AC, F0, RS1, RS0, OV, -, P so for selecting bank2 RS1=1 and RS0=0 which are fourth and third bit of the register respectively.

Detailed explanation-3: -5. Which of the following instructions affect the flags of the status register? Explanation: AND, INC, OR could affect status register flags. All arithmetic and logical instructions affect status register flags except SER Rd instruction.

Detailed explanation-4: -An 8051 Instruction consists of an Opcode (short of Operation – Code) followed by Operand(s) of size Zero Byte, One Byte or Two Bytes. The Op-Code part of the instruction contains the Mnemonic, which specifies the type of operation to be performed.

Detailed explanation-5: -The cp instruction allows us to compare two registers.