diff --git a/2ano/2semestre/ac2/aula02/AC2-P-Aula02.pdf b/2ano/2semestre/ac2/aula02/AC2-P-Aula02.pdf
new file mode 100644
index 0000000..67fab1e
Binary files /dev/null and b/2ano/2semestre/ac2/aula02/AC2-P-Aula02.pdf differ
diff --git a/2ano/2semestre/ac2/aula02/part1-ex1.c b/2ano/2semestre/ac2/aula02/part1-ex1.c
new file mode 100644
index 0000000..527b553
--- /dev/null
+++ b/2ano/2semestre/ac2/aula02/part1-ex1.c
@@ -0,0 +1,13 @@
+#include <detpic32.h>
+
+int main() {
+    int counter = 0;
+    while (1) {
+        putChar('\r');
+        printInt(counter, 10 | 4 << 16);
+        resetCoreTimer();
+        while (readCoreTimer() < 200000);
+        counter++;
+    }
+    return 0;
+}
diff --git a/2ano/2semestre/ac2/aula02/part1-ex1.s b/2ano/2semestre/ac2/aula02/part1-ex1.s
new file mode 100644
index 0000000..15c3902
--- /dev/null
+++ b/2ano/2semestre/ac2/aula02/part1-ex1.s
@@ -0,0 +1,37 @@
+	.equ READ_CORE_TIMER, 11
+	.equ RESET_CORE_TIMER, 12
+	.equ PUT_CHAR, 3
+	.equ PRINT_INT, 6
+
+	.data
+	.text
+	.globl main
+
+main:	li	$t0, 0
+
+while:	li	$a0, '\r'
+	li	$v0, PUT_CHAR
+	syscall
+
+	move	$a0, $t0
+	li	$a1, 4
+	sll	$a1, $a1, 16
+	ori	$a1, $a1, 10
+	li	$v0, PRINT_INT
+	syscall
+
+	li	$v0, RESET_CORE_TIMER
+	syscall
+
+delay:	li	$v0, READ_CORE_TIMER
+	syscall
+	move	$t1, $v0
+
+	# 20,000,000 cycles = 1 second = 1 Hz
+	# 4,000,000 cycles = 0.2 second = 5 Hz
+	# 2,000,000 cycles = 0.1 second = 10 Hz
+	blt	$t1, 20000000, delay
+
+	addi	$t0, $t0, 1
+	j	while
+
diff --git a/2ano/2semestre/ac2/aula02/part1-ex2.c b/2ano/2semestre/ac2/aula02/part1-ex2.c
new file mode 100644
index 0000000..d601326
--- /dev/null
+++ b/2ano/2semestre/ac2/aula02/part1-ex2.c
@@ -0,0 +1,16 @@
+#include <detpic32.h>
+
+void delay(unsigned int ms) {
+    resetCoreTimer();
+    while(readCoreTimer() < ms * 20000);
+}
+
+int main() {
+    int counter = 0;
+    while (1) {
+        putChar('\r');
+        printInt(counter++, 10 | 4 << 16);
+        delay(1000);
+    }
+    return 0;
+}
diff --git a/2ano/2semestre/ac2/aula02/part1-ex2.s b/2ano/2semestre/ac2/aula02/part1-ex2.s
new file mode 100644
index 0000000..cea5209
--- /dev/null
+++ b/2ano/2semestre/ac2/aula02/part1-ex2.s
@@ -0,0 +1,39 @@
+	.equ READ_CORE_TIMER, 11
+	.equ RESET_CORE_TIMER, 12
+	.equ PUT_CHAR, 3
+	.equ PRINT_INT, 6
+
+	.data
+	.text
+	.globl main
+
+main:	li	$s0, 0
+
+while:	li	$a0, '\r'
+	li	$v0, PUT_CHAR
+	syscall
+
+	move	$a0, $s0
+	li	$a1, 4
+	sll	$a1, $a1, 16
+	ori	$a1, $a1, 10
+	li	$v0, PRINT_INT
+	syscall
+
+	addu	$sp, $sp, -4
+	sw	$ra, 0($sp)
+	li	$a0, 1000
+	jal	delay
+
+	addi	$s0, $s0, 1
+	j	while
+
+delay:	li	$v0, RESET_CORE_TIMER
+	syscall
+
+count:	li	$v0, READ_CORE_TIMER
+	syscall
+	mul	$t0, $a0, 20000
+	blt	$v0, $t0, count
+
+	jr	$ra
diff --git a/2ano/2semestre/ac2/aula02/part2.c b/2ano/2semestre/ac2/aula02/part2.c
new file mode 100644
index 0000000..78dc9e5
--- /dev/null
+++ b/2ano/2semestre/ac2/aula02/part2.c
@@ -0,0 +1,38 @@
+#include <detpic32.h>
+
+void delay(unsigned int ms) {
+    resetCoreTimer();
+    while(readCoreTimer() < ms * 20000);
+}
+
+int main() {
+    int cnt1 = 0, cnt5 = 0, cnt10 = 0;
+    unsigned int ms = 100;
+    while (1) {
+        putChar('\r');
+        printInt(cnt1, 10 | 4 << 16);
+        putChar('\t');
+        printInt(cnt5, 10 | 4 << 16);
+        putChar('\t');
+        printInt(cnt10, 10 | 4 << 16);
+
+        char key = inkey();
+        switch(key) {
+            case 'S':
+                while(inkey() != 'R');
+                break;
+            case 'A':
+                ms /= 2;
+                break;
+            case 'N':
+                ms = 100;
+                break;
+        }
+
+        delay(ms);
+        if (cnt10 % 10 == 0) cnt1++;
+        if (cnt10 % 2 == 0) cnt5++;
+        cnt10++;
+    }
+    return 0;
+}
diff --git a/2ano/2semestre/ac2/aula02/part2.s b/2ano/2semestre/ac2/aula02/part2.s
new file mode 100644
index 0000000..65c2516
--- /dev/null
+++ b/2ano/2semestre/ac2/aula02/part2.s
@@ -0,0 +1,80 @@
+	.equ READ_CORE_TIMER, 11
+	.equ RESET_CORE_TIMER, 12
+	.equ PUT_CHAR, 3
+	.equ PRINT_INT, 6
+
+	.data
+	.text
+	.globl main
+
+# Mapa de registos
+# cnt1:		$s0
+# cnt5:		$s1
+# cnt10:	$s2
+
+main:	li	$s0, 0
+	li	$s1, 0
+	li	$s2, 0
+
+while:	li	$a0, '\r'
+	li	$v0, PUT_CHAR
+	syscall
+
+	move	$a0, $s0
+	li	$a1, 4
+	sll	$a1, $a1, 16
+	ori	$a1, $a1, 10
+	li	$v0, PRINT_INT
+	syscall
+
+	li	$a0, '\t'
+	li	$v0, PUT_CHAR
+	syscall
+
+	move	$a0, $s1
+	li	$a1, 4
+	sll	$a1, $a1, 16
+	ori	$a1, $a1, 10
+	li	$v0, PRINT_INT
+	syscall
+
+	li	$a0, '\t'
+	li	$v0, PUT_CHAR
+	syscall
+
+	move	$a0, $s2
+	li	$a1, 4
+	sll	$a1, $a1, 16
+	ori	$a1, $a1, 10
+	li	$v0, PRINT_INT
+	syscall
+
+	addu	$sp, $sp, -4
+	sw	$ra, 0($sp)
+	li	$a0, 100
+	jal	delay
+
+	remi	$t0, $s0, 10
+	bnez	$t0, ignore1
+	addi	$s0, $s0, 1
+	li	$s3, 0
+
+ignore1:
+	remi	$t0, $s1, 2
+	bnez	$t0, ignore5
+	addi	$s1, $s1, 1
+	li	$s4, 0
+
+ignore5:
+	addi	$s2, $s2, 1
+	j	while
+
+delay:	li	$v0, RESET_CORE_TIMER
+	syscall
+
+count:	li	$v0, READ_CORE_TIMER
+	syscall
+	mul	$t0, $a0, 20000
+	blt	$v0, $t0, count
+
+	jr	$ra