3/30/2023 0 Comments 74155 ic logicworks![]() ![]() Through this paper the authors would like to share their experience of devising various strategies, which were adapted to achieve the higher assessment integrity goals in a COVID-19 teaching environment.Ĭovid-19 pandemic, Online teaching environment, Covid-19, Assessment integrity, Education challenges Thus, there is a big challenge to maintain the assessment integrity to protect the academic integrity qualification-awarding processes. An alternative assessment arrangements to substitute an unseen written examinations, which were normally conducted in examination halls under strict invigilation are a mainstay for summative assessment in higher education. This forced adaption has brought many challenges, and opportunities throughout its managements. Schools, colleges, universities and institutions have transitioned from in-person to virtual instruction. The field of education, which is a fundamental human right for all children and youth, has severely challenged in unprecedented manner by the COVID-19 pandemic. ![]() If 74138 is not used, we have separate circuits for chip selection which results to complex circuits.The COVID-19 pandemic poses unprecedented challenges to every field of life. The lines of address ranging from A9 to A0 selects a particular location in the EPROM-7 after 74138 and here after EPROM-7 gets selected. We select EPROM-7 gets selected when the selection of 74138 is done A 12 A 11 A 10 turns to 1 1 1. 74138 is used to generate chip signals.Ī15 to A11 selects RAM A10 to A0 selects a location in RAM Hence the address of starting for EPROM-0 is depicted in the following figure -įig. ![]() The lines of address ranging from A 9-0 gets selects by the memory location in the EPROM to be 0 thereafter 74138 and EPROM-0 is finally selected. EPROM-0 gets selected when selection of 74138 is done and A 12 A 11 A 10 turns to 0 0 0. In the figure below 74138 gets selected when the addresses A 15 A 14 A 13 turns to 0 0 1. Let us suppose that there are eight 1K × 8 sized chips of EPROM, where we want the starting of address to be 2000H, 2400H, 2800H, …, 3C00H. We use the logic of selection to generate signals for chip selection tending to eight chips in a microcomputer system. Use of 74138 to generate chip select logic: So the ultimate address bit pattern has become 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 => 2000H So the address of starting becomesĪ9 to A0: Selects a location in EPROM 0 0 0 0 0 0 0 0 0 0 Here EPROM-7 gets selected when 74138 is selected and the address A 12 A 11 A 10 turns to 1 1 1. The chip 74138 gets selected when E 1* turns to 0, and E 2* is equal to 0, and E 3 is 1. Moreover, the lines of output get activated by the input, if and only if 74138 chip becomes selected. If by chance I 2 I 1 I 0 is equal to 0 1 0, then the lines of output O 2* turns to 0. Let’s take as an example that if the pins I 2 I 1 I 0 = 1 1 1, then the line of output O7* is equal to 0, rather line O 7* gets activated. The point to be noted that, only one of the lines of output which completely depends on the input pins I 2, I 1, and I 0. A power supply of +5 V DC is needed by the chip and is Grounded. The outputs are actively in low state and are eight in number and are classified as O 7*, O 6*, …, O 0*. ![]() We have three input pins which are actively in high state and are classified as I 2, I 1Īnd I 0. We take the popular 3 to 8 decoder Integrated Circuit 74138. Let’s take an Integrated Circuit decoder. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |