Short assembly program Homework .......
The task is to write an assembly program to search the data stored in the memory locations starting from 0x20001000 to 0x2000101C (total 8 data) for the smallest number and store it to the memory location 0x20002000. An equivalent C program would look like,
//This C program is only to demonstrate the flow of the homework.
int32_t i, temp=0, data[8]; //temp is equivalent to R0 register.
for (i=7; i>=0; i--) {if (temp>data[i]) temp=data[i];} //compare and keep the smaller one.
1. Assume that the data are stored in the memory at the beginning. Do not assign any specific values to them. The program should be general enough to work with any data in the memory in any order.
2. Note that a memory address increments by 4, not by 1.
3. Use the for-loop style iteration to scan all memory data in the range.
4. Use R0 to store the smallest number.
5. Use R1 to count the number of iteration.
Deliverables
vCreate a .s file in uVision and build the target. Debug your program until you get 0 error.
vWrite the class and section number, your name and Homework number at the very top in comments.
vThen submit your .s file to BBlearner. You can change your submission up to 5 times.
vDue time is the midnight of February 28 (Sun).
Hint
Use the post-offset indirect addressing to fetch data in the memory.
baseaddr equ 0x20001000
index_increment equ 4
ldr r2, =baseaddr
ldr r4, [r2], #index_increment ;fetch the data and increment r2 address
cmp r0, r4 ;compare r0 and r4
blt move_on ;if r0 is less than r4, move on. If not, replace
mov r0, r4
move_on
sub r1, r1, #1 ;decrement the counter by one.
End