Tried to fix, didn't work. Must be missing an update. Old clock -> clock.s /...

Tried to fix, didn't work. Must be missing an update. Old clock -> clock.s / New clock -> digital_clock.s

test/asm/clock.s

+.text
+# FIXME: currently only displays that which has been updated.
+
+main:
+# initialisation of the month discrimination
+# 0..0101011010101
+  addi $s0, $zero, 2773
+# TODO: change initialisation to input value (for example, linux time stamp)
+# initialisation of the value keeping the minutes and seconds
+# Format : DDDD.UUUU.dddd.uuuu where d/D = digit, u/U = unit  for sec/min
+  xor $s1, $s1, $s1
+
+# initialisation of the value keeping the hours and the days
+# Format : ddddd.HHHH.hhhh where d = day, h/H = hour (unit/digit)
+  addi $s2, $zero, 4352
+
+# initialisation of the value keeping the years
+  addi $s3, $zero, 2017
+  xor $s3, $s3, $s3
+
+# initialisation of the value counting the leap years and the month
+# Format : mmmm.ccccc where m = month, c = counter
+  addi $s4, $zero, 32
+
+# initialisation of the value keeping track of the current time
+  xor $s5, $s5, $s5
+
+# $s6 and $s7 will be used to store addresses for future jumps
+# $t6 will be used to remember which values have already been printed
+# $t7 will be used as a flag for when we are processing hours
+  j clock
+
+clock:
+# We loop until a second has passed.
+# Comment this part for performance tests.
+#  li $v0, 5
+#  syscall
+#  beq $v0, $s5, clock
+# We update the time.
+#  add $s5, $zero, $v0
+# We empty the buffer
+  la $a0, end
+  li $v0, 4
+  syscall
+# We now start the calculations for the next second.
+  j seconds
+
+print_zero:
+  la $a0, zero
+  addi $t0, $zero, 1
+  xor $a1, $a1, $a1
+  j print
+
+print_zero_digit:
+  la $a0, zero
+  addi $t0, $zero, 1
+  xor $a2, $a2, $a2
+  j print
+
+print_one:
+  la $a0, one
+  j print
+
+print_two:
+  la $a0, two
+  j print
+
+
+print_three:
+  la $a0, three
+  j print
+
+print_four:
+# HACK : $t7 = 2 when dealing with hours -> check if digit = 2
+# We test whether this is the 4 of 24 hours. If so, jump to twenty_four
+  and $t2, $t7, $a2
+  bne $t2, $zero, print_twenty_four
+  la $a0, four
+  j print
+
+# We handle the case of 24h, coming from the units.
+print_twenty_four:
+  xor $a1, $a1, $a1
+  addi $t0, $zero, 1
+  la $a0, zero
+  j print
+
+print_five:
+  la $a0, five
+  j print
+
+print_six:
+  la $a0, six
+  j print
+
+print_seven:
+  la $a0, seven
+  j print
+
+print_eight:
+  la $a0, eight
+  j print
+
+print_nine:
+  la $a0, nine
+  j print
+
+print:
+  li $v0, 4
+  syscall
+  jr $ra
+
+# To make a conditional jump to $ra
+break:
+  jr $ra
+
+# We use this block to compute the display of a unit - seconds, minutes or hours
+unit:
+  xor $t0, $t0, $t0
+  xor $v0, $v0, $v0
+# $t0 is a flag at 1 iff an update is needed
+  addi $t1, $zero, 1
+# We increment $a1
+  addi $a1, $a1, 1
+# We use $t0 as an easy way to access 0, but here $t0 = $zero
+# We set the return adress to be the digit
+  la $ra, digits
+# We test the value of $a1
+  beq $a1, $t1, print_one
+  addi $t1, $t1, 1
+  beq $a1, $t1, print_two
+  addi $t1, $t1, 1
+  beq $a1, $t1, print_three
+  addi $t1, $t1, 1
+  beq $a1, $t1, print_four
+  addi $t1, $t1, 1
+  beq $a1, $t1, print_five
+  addi $t1, $t1, 1
+  beq $a1, $t1, print_six
+  addi $t1, $t1, 1
+  beq $a1, $t1, print_seven
+  addi $t1, $t1, 1
+  beq $a1, $t1, print_eight
+  addi $t1, $t1, 1
+  beq $a1, $t1, print_nine
+  addi $t1, $t1, 1
+  beq $a1, $t1, print_zero
+
+# We use this block to compute the display of a digit - seconds, minutes, hours
+digits:
+# We set the return value
+  add $ra, $zero, $s7
+# We test if an update is necessary
+  beq $t0, $zero, break
+  add $ra, $zero, $s6
+# We test whether we reached 24 hours
+# Remember that $t2 = 2 when we deal with hours.
+  bne $t2, $zero, print_zero_digit
+  xor $t0, $t0, $t0
+  addi $a2, $a2, 1
+  addi $t1, $zero, 1
+# We test the value of $a2
+  beq $a2, $t1, print_one
+  addi $t1, $t1, 1
+  beq $a2, $t1, print_two
+  addi $t1, $t1, 1
+  beq $a2, $t1, print_three
+  addi $t1, $t1, 1
+  beq $a2, $t1, print_four
+  addi $t1, $t1, 1
+  beq $a2, $t1, print_five
+  addi $t1, $t1, 1
+  beq $a2, $t1, print_zero_digit
+
+# The following blocks compute a possible update of the month.
+# This is where we compute whether it is a leap year or not.
+day_29:
+# We are sent here from the tests on the day
+# $a1 is the day, $a2 is the month
+  addi $t4, $zero, 2
+  bne $a2, $t4, update_days
+# We test whether the year is a leap year
+# First, if the modulo is 4
+  andi $t4, $s3, 3
+  beq $t4, $zero, year_100
+  addi $t0, $zero, 1
+  j update_days
+
+# Then, if it is a multiple of four, whether our leap year counter is 25
+year_100:
+# Update the counter first.
+  addi $s4, $s4, 1
+  addi $t4, $zero, 25
+  beq $s4, $t4, year_400
+
+# If we didn't jump, it's a leap year.
+leap_year:
+# The day should be 1
+  addi $a1, $zero, 1
+  addi $t0, $zero, 1
+  j update_days
+
+year_400:
+# We need to reset our counter
+  xor $s4, $s4, $s4
+# We test whether the year is a multiple of 400
+# If it is, it's a leap year
+  andi $t4, $a1, 15
+  beq $t4, $zero, leap_year
+  addi $a1, $a1, 1
+  j update_days
+
+# This is to test whether we are a 29/02
+day_30:
+  addi $t4, $zero, 2
+  bne $a2, $t4, update_days
+# If this is indeed a 29/02
+  addi $a1, $zero, 1
+  addi $t0, $zero, 1
+  j update_days
+
+day_31:
+# We use the discrimination from $s0 to decide if a month has 30 or 31 days
+  srlv $t4, $s0, $a2
+  andi $t4, $t4, 1
+# $t4 = 0 if the month has 30 days, $t4 = 1 otherwise
+  bne $t4, $zero, update_days
+# j day_32
+
+# Here, we always need to update the month.
+day_32:
+  addi $a1, $zero, 1
+  addi $t0, $zero, 1
+  j update_days
+
+# For when we need to roll around to a new year
+month_13:
+  addi $a2, $zero, 1
+  addi $t0, $zero, 1
+  j update_months
+
+
+# Beginning of each loop
+seconds:
+  xor $t7, $t7, $t7
+  xor $a1, $a1, $a1
+  xor $a2, $a2, $a2
+# We fetch the stored values of the seconds
+  andi $a1, $s1, 15
+  andi $a2, $s1, 240
+  srl $a2, $a2, 4
+# We empty the print argument
+  xor $a0, $a0, $a0
+  xor $t0, $t0, $t0
+# $t2 is the flag for when we reached 24h.
+  xor $t2, $t2, $t2
+  la $s7, update_sec_units
+  la $s6, update_sec_digits
+  j unit
+
+update_sec_digits:
+# Update the digits
+  andi $s1, $s1, 65295
+  sll $a2, $a2, 4
+  or $s1, $a2, $s1
+
+update_sec_units:
+# Update the units
+  andi $s1, $s1, 65520
+  or $s1, $a1, $s1
+  beq $t0, $zero, clock
+#  j minutes
+
+minutes:
+  xor $a0, $a0, $a0
+  xor $a1, $a1, $a1
+  xor $a2, $a2, $a2
+  xor $t0, $t0, $t0
+# We fetch the stored values of the minutes
+  andi $a1, $s1, 3840
+  srl $a1, $a1, 8
+  andi $a2, $s1, 61440
+  srl $a2, $a2, 12
+  la $s7, update_min_units
+  la $s6, update_min_digits
+  j unit
+
+update_min_digits:
+# Update the digits
+  andi $s1, $s1, 4095
+  sll $a2, $a2, 12
+  or $s1, $a2, $s1
+
+update_min_units:
+# Update the units
+  andi $s1, $s1, 61695
+  sll $a1, $a1, 8
+  or $s1, $a1, $s1
+  beq $t0, $zero, clock
+#  j hours
+
+hours:
+  xor $a0, $a0, $a0
+  xor $a1, $a1, $a1
+  xor $a2, $a2, $a2
+  xor $t0, $t0, $t0
+# We are treating the hours, so $t7 = 2
+  addi $t7, $zero, 2
+# We fetch the stored values of the hours
+  andi $a1, $s2, 15
+  andi $a2, $s2, 240
+  srl $a2, $a2, 4
+# We set the return adresses
+  la $s7, update_hours_units
+  la $s6, update_hours_digits
+  j unit
+
+update_hours_digits:
+# Update the digits
+  andi $s2, $s2, 65295
+  sll $a2, $a2, 4
+  or $s2, $a2, $s2
+
+update_hours_units:
+# Update the units
+  andi $s2, $s2, 65520
+  or $s2, $a1, $s2
+  beq $t0, $zero, clock
+#  j days
+
+days:
+  xor $a0, $a0, $a0
+  xor $a1, $a1, $a1
+  xor $a2, $a2, $a2
+  xor $t0, $t0, $t0
+# We fetch the current day and month
+  andi $a1, $s2, 7936
+  srl $a1, $a1, 8
+  andi $a2, $s4, 480
+  srl $a2, $a2, 5
+# We update the day
+  addi $a1, $a1, 1
+# We have some tests to do according to the next day
+  addi $t3, $zero, 29
+  beq $a1, $t3, day_29
+  addi $t3, $t3, 1
+  beq $a1, $t3, day_30
+  addi $t3, $t3, 1
+  beq $a1, $t3, day_31
+  addi $t3, $t3, 1
+  beq $a1, $t3, day_32
+# If we haven't jumped, we must stay in the same month
+
+update_days:
+# We print the new day
+  add $a0, $zero, $a1
+  li $v0, 1
+  syscall
+  la $a0, line
+  li $v0, 4
+  syscall
+# Screen $s2 to erase the days
+  andi $s2, $s2, 255
+  sll $a1, $a1, 8
+  or $s2, $a1, $s2
+  beq $t0, $zero, clock
+# j months
+
+months:
+  xor $t0, $t0, $t0
+# At this point, $a2 already contains the month
+  addi $a2, $a2, 1
+  addi $t4, $zero, 13
+  beq $a2, $t4, month_13
+# j update_months
+
+update_months:
+# We print the new month
+  add $a0, $zero, $a2
+  li $v0, 1
+  syscall
+  la $a0, line
+  li $v0, 4
+  syscall
+# Screen $s3 to erase the month
+  andi $s4, $s4, 31
+  sll $a2, $a2, 5
+  or $s4, $s4, $a2
+  beq $t0, $zero, clock
+# j years
+
+years:
+# We only have to add 1 to the current year.
+  addi $s3, $s3, 1
+# We print the new year
+  add $a0, $zero, $s3
+  li $v0, 1
+  syscall
+  la $a0, line
+  li $v0, 4
+  syscall
+# Time to restart the loop
+  j clock
+
+.data
+  zero: .asciiz "1011111\n"
+  one: .asciiz "0000110\n"
+  two: .asciiz "0111011\n"
+  three: .asciiz "0101111\n"
+  four: .asciiz "1100110\n"
+  five: .asciiz "1101101\n"
+  six: .asciiz "1111101\n"
+  seven: .asciiz "0000111\n"
+  eight: .asciiz "1111111\n"
+  nine: .asciiz "1101111\n"
+  line: .asciiz "\n"
+  end: .asciiz "EOF\n"

test/asm/digital_clock.s

@@ -6,24 +6,18 @@ main:
 # 0..0101011010101
   addi $s0, $zero, 2773
 # TODO: change initialisation to input value (for example, linux time stamp)
-# initialisation of the value keeping the minutes and seconds
-# Format : DDDD.UUUU.dddd.uuuu where d/D = digit, u/U = unit  for sec/min
-  xor $s1, $s1, $s1
-
-# initialisation of the value keeping the hours and the days
-# Format : ddddd.HHHH.hhhh where d = day, h/H = hour (unit/digit)
-  addi $s2, $zero, 4352
-
-# initialisation of the value keeping the years
-  addi $s3, $zero, 2017
-  xor $s3, $s3, $s3
+  xor $s1, $s1, $s1 #day
+  xor $s2, $s2, $s2 #month
+  xor $fp, $fp, $fp #unit hour
+  xor $sp, $sp, $sp #digit hour
+  xor $t8, $t8, $t8 #unit minute
+  xor $t9, $t9, $t9 #digit minute
+  xor $k0, $k0, $k0 #unit second
+  xor $k1, $k1, $k1 #digit second
 
 # initialisation of the value counting the leap years and the month
 # Format : mmmm.ccccc where m = month, c = counter
-  addi $s4, $zero, 32
-
-# initialisation of the value keeping track of the current time
-  xor $s5, $s5, $s5
+  xor $s4, $s4, $s4
 
 # $s6 and $s7 will be used to store addresses for future jumps
 # $t6 will be used to remember which values have already been printed
@@ -246,8 +240,8 @@ seconds:
   xor $a1, $a1, $a1
   xor $a2, $a2, $a2
 # We fetch the stored values of the seconds
-  andi $a1, $s1, 15
-  andi $a2, $s1, 240
+  add $a1, $zero, $k0
+  add $a2, $zero, $k1
   srl $a2, $a2, 4
 # We empty the print argument
   xor $a0, $a0, $a0
@@ -260,16 +254,12 @@ seconds:
 
 update_sec_digits:
 # Update the digits
-  andi $s1, $s1, 65295
-  sll $a2, $a2, 4
-  or $s1, $a2, $s1
+  add $k1, $zero, $a2
 
 update_sec_units:
 # Update the units
-  andi $s1, $s1, 65520
-  or $s1, $a1, $s1
+  add $k0, $zero, $a1
   beq $t0, $zero, clock
-#  j minutes
 
 minutes:
   xor $a0, $a0, $a0
@@ -277,25 +267,19 @@ minutes:
   xor $a2, $a2, $a2
   xor $t0, $t0, $t0
 # We fetch the stored values of the minutes
-  andi $a1, $s1, 3840
-  srl $a1, $a1, 8
-  andi $a2, $s1, 61440
-  srl $a2, $a2, 12
+  add $a1, $zero, $t8
+  add $a2, $zero, $t9
   la $s7, update_min_units
   la $s6, update_min_digits
   j unit
 
 update_min_digits:
 # Update the digits
-  andi $s1, $s1, 4095
-  sll $a2, $a2, 12
-  or $s1, $a2, $s1
+  add $t9, $zero, $a2
 
 update_min_units:
 # Update the units
-  andi $s1, $s1, 61695
-  sll $a1, $a1, 8
-  or $s1, $a1, $s1
+  add $t8, $zero, $a1
   beq $t0, $zero, clock
 #  j hours
 
@@ -307,9 +291,8 @@ hours:
 # We are treating the hours, so $t7 = 2
   addi $t7, $zero, 2
 # We fetch the stored values of the hours
-  andi $a1, $s2, 15
-  andi $a2, $s2, 240
-  srl $a2, $a2, 4
+  add $a1, $zero, $fp
+  add $a2, $zero, $sp
 # We set the return adresses
   la $s7, update_hours_units
   la $s6, update_hours_digits
@@ -317,14 +300,11 @@ hours:
 
 update_hours_digits:
 # Update the digits
-  andi $s2, $s2, 65295
-  sll $a2, $a2, 4
-  or $s2, $a2, $s2
+  add $sp, $zero, $a2
 
 update_hours_units:
 # Update the units
-  andi $s2, $s2, 65520
-  or $s2, $a1, $s2
+  add $fp, $zero, $a1
   beq $t0, $zero, clock
 #  j days
 
@@ -334,10 +314,8 @@ days:
   xor $a2, $a2, $a2
   xor $t0, $t0, $t0
 # We fetch the current day and month
-  andi $a1, $s2, 7936
-  srl $a1, $a1, 8
-  andi $a2, $s4, 480
-  srl $a2, $a2, 5
+  add $a1, $zero, $s1
+  add $a2, $zero, $s2
 # We update the day
   addi $a1, $a1, 1
 # We have some tests to do according to the next day
@@ -359,10 +337,7 @@ update_days:
   la $a0, line
   li $v0, 4
   syscall
-# Screen $s2 to erase the days
-  andi $s2, $s2, 255
-  sll $a1, $a1, 8
-  or $s2, $a1, $s2
+  add $s1, $zero, $a1
   beq $t0, $zero, clock
 # j months