Match the following : Codes :List - I List - II (a) 24C01 (i) Parallel EPROM (b) 28C64 (ii) EPROM (c) 74S288 (iii) Serial EEPROMS (d) 27C010 (iv) TTL PROM
(a)-(iii), (b)-(i), (c)-(iv), (d)-(ii)
The part numbers themselves carry the family, and once that is known each entry falls into place.
(a) 24C01 → (iii) serial EEPROM. The 24Cxx series is the ubiquitous I2C EEPROM — two wires (SDA and SCL), an 8-pin package, and capacities from 128 bytes (24C01, 1 kilobit) upwards. Being serial, it needs almost no pins, which is why it appears on every circuit board that must remember a few settings.
(b) 28C64 → (i) parallel EEPROM. The 28Cxx series is the parallel-bus counterpart: a full address and data bus, so it drops directly into a microprocessor memory map. The 28C64 is 64 kilobits, 8K × 8. (List-II's label reads "Parallel EPROM", but the C in 28C64 and the 28 prefix mark it as electrically erasable.)
(c) 74S288 — (iv) TTL PROM. The 74 prefix is the TTL logic family, and the S denotes Schottky TTL. The 74S288 is a 32 × 8 bipolar PROM programmed once by blowing nichrome fusible links — fast, tiny and permanent, the sort of part used for a small look-up table or address decoder.
(d) 27C010 → (ii) EPROM. The 27xxx series is the classic UV-erasable EPROM with its quartz window; the C indicates a CMOS process, and 010 marks 1 megabit, 128K × 8.
| Prefix | Family | Erased by | Interface |
|---|---|---|---|
| 24Cxx | Serial EEPROM | Electrically, per byte | I2C, 2 wires |
| 27xxx | EPROM | Ultraviolet light | Parallel |
| 28Cxx | Parallel EEPROM | Electrically, per byte | Parallel |
| 74Sxxx | Bipolar PROM | Not erasable | Parallel |
The order (iii), (i), (iv), (ii) is option 1.
The pattern worth memorising is the 24 / 27 / 28 distinction: 24 is serial, 27 is UV-erasable, 28 is electrically erasable and parallel. Those three prefixes cover most non-volatile memories a candidate will meet, and the numeric suffix generally gives the capacity in kilobits.
Hence, the correct match is (a)-(iii), (b)-(i), (c)-(iv), (d)-(ii).
Similar Questions
EPROM stands for :
Assertion (A) : Flash memory is non-volatile memory that can be electrically erased and reprogrammed.
Reason (R) : Flash memory is a specific type of EEPROM that is erased and programmed, in-circuit, in large blocks in contrast to EEPROM which is erased and reprogrammed at the byte level.
Select your answer using the codes given below :
Important Questions from Semiconductor Memories
Each cell of a static RAM contains
Which of the following memories can be programmed once by the user and then cannot be erased and reprogrammed?
- How many storage locations are available when a memory device has 12 address lines?
How many bits are in a byte?
Class of mass memory devices that use a laser beam to write and read on to a specified coated disk
