Match each device in List I with its IC number in List II, and select the…
2012
Match each device in List I with its IC number in List II, and select the sequence that gives the four matches in order (i)–(iv).
Item | List I — Device | Match | List II — IC number |
|---|---|---|---|
(i) | USART | (a) | 8251 |
(ii) | Microcontroller | (b) | 8051 |
(iii) | Interrupt controller | (c) | 8259 |
(iv) | DMA controller | (d) | 8257 |
Answer: A. USART–8251; Microcontroller–8051; Interrupt controller–8259; DMA controller–8257 — ConceptPeripheral-controller ICs are identified by their intended hardware function. A serial communication controller, a microcontroller, an interrupt…
- A.
USART–8251; Microcontroller–8051; Interrupt controller–8259; DMA controller–8257
- B.
USART–8051; Microcontroller–8251; Interrupt controller–8257; DMA controller–8259
- C.
USART–8259; Microcontroller–8257; Interrupt controller–8251; DMA controller–8051
- D.
USART–8257; Microcontroller–8251; Interrupt controller–8051; DMA controller–8259
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Show answer & explanation
Correct answer: A
Concept
Peripheral-controller ICs are identified by their intended hardware function. A serial communication controller, a microcontroller, an interrupt controller, and a DMA controller are distinct functional classes, so the chip number should be matched by function rather than by numerical similarity.
Application
8251 is Intel’s programmable communication interface (USART), used for synchronous or asynchronous serial data communication.
8051 denotes the MCS-51 single-chip microcontroller family, which combines a CPU, memory, and peripherals on one chip.
8259 is a programmable interrupt controller, used to prioritize and service interrupt requests.
8257 is a programmable DMA controller, used to transfer data between memory and input/output devices without CPU handling each byte.
Cross-check and contrast
8251 corresponds to serial communication.
8051 corresponds to integrated computation and control.
8259 corresponds to interrupt arbitration.
8257 corresponds to direct data movement.
Therefore, the mapping in the order (i)–(iv) is USART–8251, Microcontroller–8051, Interrupt controller–8259, and DMA controller–8257; equivalently, the sequence is (a), (b), (c), (d).