EE 308 Spring 2012EE 308 – Homework 2Due Feb. 1, 20121. Write an instruction sequence to take the unsigned 8-bit number in memory location $1000,divide it by two, and put the result into memory lo c ation $1100. Also, take the unsigned8-bit number at memory location $1100, divide it by two, and put the result into memorylocation $1000. If $1000 orignally had a 17, and $1100 originally had a 22, then after theinstructions are executed, $1000 should have am 8 and $1100 should have a 12.2. Problem E1.18 (Page 37 of text).3. Problem E1.19 (Page 37 of text).4. Consider Program 1 from Lab 2:prog: equ $2000 ; Starting address from programdata: equ $1000 ; Starting address for dataorg prog ; Set initial program counter valueldy #2345 ; Immediate (IMM) addressing modeldab #123aby ; Inherent (INH) addressing modesty result ; Extend (EXT) addressing modeswiorg data ; Put data starting at this locationresult: ds.w 1 ; Reserve one word (two bytes) for results(a) Hand-assemble the program. That is, figure out what the op codes of the instructionsare, and where they will be located in memory.(b) How many cycles will it take the MC9S12 to execute this program. (Do not include theswi instruction.)(c) How long will it take an MC9S12 with a 24 MHz E clock to execute this program?(d) Determine the state of the N, Z, V and C bits after each instruction has been executed.(Assume that, when the program starts, all these bits are zero.)(e) What will be the contents of addresses $1000 and $1001 after the program executes?5. Consider Program 2 from Lab 2:prog: equ $2000 ; Starting address for programdata: equ $1000 ; Starting address for datacount: equ 10 ; 10 elements in the tableorg progldaa #count ; ACCA keeps count of numbers left in tableldx #table ; X points to table of dataldy #0 ; Y holds sum; initialize to 01EE 308 Spring 2012repeat: ldab 1,X+ ; get data from table int B; X points to next elementaby ; Compute 16-bit sumdeca ; Decrement counterbne repeat ; If not done, continue with next elementsty result ; Save sumswiorg data ; Put data starting at this location; Initialize data in tabletable: dc.b $44,$AB,$74,$61,$C2,$54,$61,$62,$F2,$13result: ds.w 1(a) Hand assemble the program. Indicate the addressing mode for each of the instructions6. Write an instruction sequence to set the lower four bits of the number at address $0049 to 0,and leave the upper four bits unchanged.7. Problem E2.17 (Page 86 of the text).8. Problem E2.19.2EE 308 Spring 20129. Consider the following program fragment:ldy #50000loop1: ldaa #250loop2: dbne a,loop2dbne y,loop1swi(a) Hand assemble the program. (Add an org assembler directive to put the program inmemory starting at address 0x2000.)(b) How many instruction cycles will it take the MC9S12 to execute the program? (Do notconsider the swi instruction.)(c) How many seconds will this take the MC9S12 with an 24 Mhz E-clock? (You shouldgive the answer to the nearest microsecond.)10. An MC9S12 has the following data in its memory:0 1 2 3 4 5 6 7 8 9 A B C D E F10D0 10 E5 3B 7C 10 04 86 80 B7 10 25 3B FC 10 26 F310E0 10 D4 A5 10 18 86 40 B7 10 23 3B FC 10 12 DD 0210F0 86 CE A2 53 1A 2F A3 10 03 86 40 B7 10 25 3B 86Determine the contents of the A and X register after executing the following code fragments.(Before the first instruction, the X register has $0000.) List the values in hexadecimal. Also,indicate what addressing mode is used, and what the effective address of the instruction is.(Assume that the first instruction is at address $2000, and that the instructions that followare in subsequent locations – i.e., the instruction of (a) takes two bytes, so the first instructionof (b) is at address $2002.)(a) ldaa #21(b) ldx $10E7(c) ldx $10E0ldaa -2,X(d) ldx #$10E0ldaa -2,X(e) ldx #$10E0ldaa 2,+X(f) ldx #$10E0ldaa
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