Accounts Analysis

    ; 1. Code the following IF-THEN statement: ; ; if (r2 != r7) ; r2 = r2 - r7; ; else ; r2 = r2 + r4; ; ; Your code have to work with any numbers in R2, R7 and R4 ; (5, 25(0x19)) ; MOVW R2, #10 MOVW R7, #5 MOVW R4, #15 ; ; MOVW R2, #10 ; MOVW R7, #10 ; MOVW R4, #15 ; ;-- Your instructions here --- ;-- Approx. 3 instructions --- --------------------------------------------------------------------------------------------------------------------- ; 2. Write a program that converts a hexadecimal value between 0x0 and 0xf in register ; R0 into its ASCII representation. Store ASCII representation into R1. ; ; Digits '0' through '9' are represented with the ASCII codes 0x30 to 0x39. The digits ; 'A' through 'F' are coded as 0x41 through 0x46. (See 'ascii.pdf' file) ; ; Test your code with R0 = 15, 0 and 9 ; (0x46, 0x30, 0x39) ; MOV R0, #15 ; MOV R0, #0 ; MOV R0, #9 ;-- Your instructions here --- --------------------------------------------------------------------------------------------------------------------- ; ; 3. Modify the code you did for task #2 to check for valid number (0..15) in R0. ; Store '*' (0x2a) into R1 if R0 is out of valid range. Store ASCII representation ; for valid numbers (from 0 to 15 inclusive). ; ; Test your code with R0 = 255, 15, 0, 9, 12 and 16 ; (0x2a, 0x46, 0x30, 0x39, 0x43, 0x2a) ; MOV R0, #255 ; MOV R0, #15 ; MOV R0, #0 ; MOV R0, #9 ; MOV R0, #12 ; MOV R0, #16 ;-- Your instructions here --- --------------------------------------------------------------------------------------------------------------------- ; ; 4. Write a program that counts number of binary '1's and number of binary '0's in R0. ; Save number of '1's into R1, number of '0's in R2. You may use any other register(s) and ; do not need to preserve the value of R0 register. ; ; Your code have to work with any number in R0 ; ; Debug your program with tets values R0 = 0xAAAAAAAA and R0 = 0x55555555. Both should give ; you 16 1's and 16 0's ; ; Then run your progarm with R0 = 0x708. Is your result correct? (use online converter to check) MOV R0, #0xAAAAAAAA ; MOV R0, #0x55555555 ; MOVW R0, #0x708 ;-- Your instructions here --- --------------------------------------------------------------------------------------------------------------------- ; ; 5. Write a "shift, test and restore" division algorithm (See "Binary Division.pdf" for details). ; ; For i = 1 to 32 do { we're using 32-bit representations } ; { ; Left Shift the RQ pair ; Subtract the Divisor from R ; If R is positive then ; Set the low order (right most) bit in Q to 1 ; Else ; Restore R by Adding back the Divisor ; } ; ; R0 = remainder (R) ; R1 = divident/quotient (Q) ; R2 = divisor (D) ; ; R1,R0 = R1/R2 ; ; Do not use UDIV and SDIV ARM commands! ; ; Your code have to work with any valid numbers in R0. You may use any other register(s). Check your ; code with given values first. Then try some another numbers in R1 and R2. MOVW R1, #163 ; 163/10 = 16, 3 MOVW R2, #10 ;-- Your instructions here --- --------------------------------------------------------------------------------------------------------------------- ; ; 6. Write a small program to compare two 64-bit values. Set R0 to 0 if two values ; are equal, set R0 to 1 if two values are not equal. First 64-bit number placed into ; R1(HI bits) and R2(LO bits), second number is in R3(HI bits) and R4(LO bits). Use only ; 4 ARM instructions! ; ; Your code have to work with any numbers in R1-R4 ; ; Check your code with all test sets below ; MOV R1, #0xAAAAAAAA MOV R2, #0x55555555 MOV R3, #0xAAAAAAAA MOV R4, #0x55555555 ; ---- ; MOV R3, #0x55555555 ; MOV R4, #0xAAAAAAAA ; ---- ; MOV R3, #0xAAAAAAAA ; MOV R4, #0xAAAAAAAA ; ---- ; MOV R3, #0x55555555 ; MOV R4, #0x55555555 ;-- Your 4 instructions here --- --------------------------------------------------------------------------------------------------------------------- ; ; 7. (Bonus). Write a code that allows you to rotate 64-bit values in registers ; R0 and R1. The code should shift value left... ; ; +--------------------+ +--------------------+ ; +<-! R0 !<--! R1 !<--+ ; ! +--------------------+ +--------------------+ ! ; ! ! ; +-->---------------------->------------------------->+ ; ; ...then right by one bit. ; ; +--------------------+ +--------------------+ ; +->! R0 !-->! R1 !-->+ ; ! +--------------------+ +--------------------+ ! ; ! ! ; +<------------------------<-----------------------<--+ ; ; - Do not use any other registers. ; ; - Make sure that after two shifts the final value is equal to original one. ; ; Tip: Left shift is tricky. You may remember: a << 1 = a * 2; a * 2 = ??? ; ... and take care of LSB... ; ; Check your code with all 3 test sets below: ; MOVW R0, #0x0001 MOVT R0, #0x8000 MOVW R1, #0x0001 MOVT R1, #0x8000 ; ---- ; MOVW R0, #0xAAAA ; MOVT R0, #0x8555 ; MOVW R1, #0x0F0F ; MOVT R1, #0xF0F0 ; ---- ; MOV R0, #0x00000001 ; MOV R1, #0x00000001 ; ; -- left -- ;-- Your instructions here --- ;-- May be done in 3 instructions --- ; -- right -- ;-- Your instructions here --- ;-- May be done in 3 instructions --- --------------------------------------------------------------------------------------------------------------------- ; 8. (Bonus++). Write a program that check if the binary pattern 2_11001010 are presented at least once ; somewhere in the number R0. The program should set R1 to 1 if the pattern is found, and clear R1 to 0 ; if no pattern in the R0. ; ; Your code have to work with any number in R0 ; ; Your code have to preserve (do not change) the value in R0 ; ; You may use any other registers ; ; Examples: the number 2_11001101100100101111001010101100 (0xCD92F2AC) has the pattern inside ; -------- ; 2_11001100110011001100110110010100 (0xCCCCCD94) has the pattern inside ; -------- ; 2_11011010101101110011100111010101 (0xDAB739D5) - no pattern ; MOVW R0, #0xF2AC MOVT R0, #0xCD92 ;--- ; MOVW R0, #0xCD94 ; MOVT R0, #0xCCCC ;--- ; MOVW R0, #0x39D5 ; MOVT R0, #0xDAB7 ;-- Your instructions here ---