ECE 353 Introduction to Microprocessor SystemsMemory MapsDraw the Memory MapMemory Maps ContinueQuiz ReviewLogic CompatibilityWriting Code FragmentSlide 8Write a SubroutineShort AnswersSlide 11Wrapping UpECE 353Introduction to Microprocessor SystemsReview/Assessment Slides for Quiz #2Memory MapsAssume that a microprocessor has a 20-bit address bus, an 8-bit data bus, and /RS, /WS control signals. Use only AND/OR/NAND/NOR gates with any number of direct or inverted inputs to implement the given memory map for the three 8-bit output ports shown below. The broadcast address area should result in a simultaneous write to all three ports. Reads should not affect the ports.Draw the Memory MapMemory Maps ContinueGiven the memory map shown, determine the logic required to implement the MEMX chip-select line. Is this okay for a RAM? A ROM?How big is the RAM?How big is the ROM?00000h3FFFFhRAM70000h8FFFFhMEMXF8000hFFFFFhROMQuiz ReviewHow many bits must be included in the decoding logic to exhaustively decode a chip-select for a 128KB ROM at address E0000h?If the decoding logic actually used two fewer bits (A19,A17 not used), what would the effect on the memory map be?You require 64K x 8 of memory, but only have 32K x 4 devices. Show how you can interconnect them to get the desired result.Logic CompatibilityWhat are the noise marginsAre these devices compatible?74AHC1G0074A HC1G0274AHC1GxxVOHminVIHminVOLmaxVILmaxIOHmaxIIHmaxIOLmaxIILmaxANDVCC=2.0V1.9V 1.5V 0.1V 0.5V -50μA +1μA +50μA -1μANORVCC=3.0V2.9V 2.1V 0.1V 0.9V -50μA +1μA +50μA -1μAWriting Code FragmentWrite a code fragment that uses a look-up table to convert the least-significant four bits of a register to its ASCII hexadecimal equivalent (0-9, A-F). Provide the complete table. Assume that the value to convert is in R0. Do not make any other assumptions about R0.Writing Code FragmentWrite a code fragment to implement the expression shown below, but without using any branches.if(R7 is odd) then R7=R7*4 else R7=R7/4Write a SubroutineWrite a subroutine that will efficiently convert an ASCIIZ string representing a number to its corresponding binary value in R0. The number will be in the form X_YYYY... where X is the number base (2-9) and Y YYY... are the digits of the number. (This is the same form supported by the ARM assembler, i.e. 2_01100 represents the value 1210.) The string will consist of only valid characters, at least one digit, and the null terminator. (So, you do not have to check the “_” character – it will be there!) Assume that the conversion will not overflow. If you received the ASCII string “8_15” (1310), you would return 0x0000000D in R0. Do not corrupt any of the caller’s registers. Comment your code!Short AnswersWhat are the relative merits of exhaustive decoding versus partial decoding?Short AnswersMicroprocessor supervisors often claim to provide brown-out protection. What is a brown-out? What does the supervisor do if it detects a brown-out, and why?Wrapping UpQuiz #2 will be held on 04/10/2008 from 7:15-8:30pm in