Programming Homework Help

Skeleton file:

.org 0x10000000

# Initializations

li $sp, 0x10fffffc # Starting address of empty stack

li $s0, 0xf0000000 # UART base address

li $s1, array_ptr # Array head pointer

li $s2, array_ptr # Array tail pointer

j main

nop

array_ptr:# Label pointing to 100 word array

.space 100

main:

jal poll_UART

nop

jal period_check

nop

jal space_check

nop

jal case_check

nop

jal array_push

nop

j main

nop

# The “poll_UART” function should poll the status register of the UART.

# If the 2^1 bit position (ready bit) is set to 1 then it

# should copy the receive buffer’s value into $v0 and send

# a clear status command (2^1) to the command register before

# returning (return statement is already included)

poll_UART:

jr $ra

nop

# The “period_check” function should check if the current character ($v0)

# is a period (“.”). If it is then it should make a jump to the label,

# “paldindrome_check”. If the character is not a period then it

# should use the included return.

period_check:

jr $ra

nop

# The “space_check” function should check if the current character ($v0)

# is a space (” “). If it is then it should jump to “main” so

# that it skips saving the space character. If not it should

# use the included return.

space_check:

jr $ra

nop

# The “case_check” function should check if the current character ($v0)

# is a lowercase character (i.e. greater than the ASCII value of ‘Z’).

# If it is then it should convert the value of $v0 to the uppercase

# equivalent before returning. If it is already uppercase then it

# should skip converting and return.

case_check:

jr $ra

nop

# The “array_push” function should save the current character ($v0) to

# the end of the array using the tail pointer, $s2, then update the tail

# pointer to point to the next element in the array before returning.

array_push:

jr $ra

nop

# The “palindrome_check” subroutine should should be jumped to by the period

# check function if a period is encountered. This subroutine should contain

# a loop that traverses the array from the front towards the back (using the

# head pointer, $s1) and from the back towards the front(using the tail

# pointer, $s2). If the string is a palindrome then as the array is traversed

# the characters pointed to should be equal. If the characters are not equal

# then the string is not a palindrome and the print function should be used

# to print “No”. If the pointers cross (i.e. the head pointer’s address is

# greater than or equal to the tail pointer’s address) and the compared

# characters are equal then the string is a palindrome and “Yes” should be

# printed. Remember to restore the head and tail pointers to the first element

# of the array before the subroutine jumps back to main to begin processing the

# next string.

palindrome_check:

j main

nop