Microprocessors And Microcontrollers - Study Mode

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[#211] Consider the following statements: The 8259A Programmable Interrupt Controller can 1. manage eight interrupts 2. vector an interrupt request anywhere in the memory map 3. have 8-bit or 16-bit interval between interrupt vector locations 4. be initialized with operational command words Which of the above statements are correct?

(A) 1, 2 and 3 only

(B) 1, 2 and 4 only

(C) 3 and 4 only

(D) 1, 2, 3 and 4

Correct Answer

(B) 1, 2 and 4 only

[#212] A controller that takes control of the buses and transfers data directly between source and destination bypassing the microprocessor is known as

(A) DMA controller

(B) read-write controller

(C) high-speed controller

(D) master-slave controller

Correct Answer

(A) DMA controller

[#213] In a 8051 microcontroller, PCON register controls the baud rate in: 1. Synchronous transmission 2. Asynchronous transmission

(A) 1 only

(B) 2 only

(C) Both 1 and 2

(D) Neither 1 nor 2

Correct Answer

(B) 2 only

[#214] In 8051 family instructions, which one of the following option is true?

(A) An opcode is one byte long for each instruction

(B) An opcode has variable number of bits in instruction

(C) An opcode must have operands specified in each instruction

(D) An opcode cannot coexist with the PC bits

Correct Answer

(A) An opcode is one byte long for each instruction

[#215] If the operating frequency of an 8086 microprocessor is 10 MHz and, if for the given instruction, the machine cycle consists of 4 T-states, what will be the time taken by the machine cycle to complete the execution of that machine cycle to complete the execution of that same instruction when three wait states are inserted?

(A) 0.4 µs

(B) 0.7 µs

(C) 7 µs

(D) 70 µs

Correct Answer

(B) 0.7 µs