Dealing with Millis Documentation and git rebase (#18) (#30)

doc/index.rst

@@ -13,4 +13,6 @@ The standard embedded firmware library is a common library for Waterloo Rocketry
    spi_driver.rst
    pwm_driver.rst
    adc_driver.rst
+   millis.rst
+
    main_func.rst

doc/millis.rst

@@ -0,0 +1,46 @@
+Timer Module Documentation
+===========================
+
+Overview
+--------
+This module provides basic timer functionalities, such as initializing Timer0, handling interrupts, and tracking milliseconds since the timer was started.
+
+.. _timer0_init:
+
+timer0_init
+-----------
+Initializes Timer0 for time tracking. This function must be called before using any other timer-related functionality.
+
+- Enables Timer0 interrupt.
+- Sets the timer to 8-bit mode.
+- Driven by a 500 kHz clock.
+- Ensures the timer is synchronized to the system clock.
+
+.. code-block:: c
+
+   void timer0_init(void);
+
+.. _timer0_handle_interrupt:
+
+timer0_handle_interrupt
+------------------------
+This function should be called from the main Interrupt Service Routine (ISR) whenever the Timer0 interrupt is triggered. It updates the internal time counter. Note that this function does **not** clear the interrupt flag (`PIR3bits.TMR0IF`); this must be done at the ISR level.
+
+.. code-block:: c
+
+   void timer0_handle_interrupt(void);
+
+.. _millis:
+
+millis
+------
+Returns the number of milliseconds since `timer0_init()` was called. This is a safe function that disables interrupts momentarily to return a consistent value.
+
+.. code-block:: c
+
+   uint32_t millis(void);
+
+Definitions and Notes
+---------------------
+- **ISR Responsibility**: The function `timer0_handle_interrupt()` does not clear the Timer0 interrupt flag. This is the responsibility of the top-level ISR.
+- **Time Precision**: The module keeps track of milliseconds, and the value returned by `millis()` reflects the time passed since the timer was initialized.