cleanup code and write a little documentation

doc/source/firmware/index.rst

@@ -15,4 +15,4 @@ mechanisms and the behavior. For a detailed code documentation see the doxygen o
 	safety/index
 	code/index
 	hw-version-detect
-
+	peripherals

doc/source/firmware/peripherals.rst

@@ -0,0 +1,44 @@
+.. _peripherals:
+
+Used Peripheral Modules
+=======================
+
+This section lists all the used peripheral modules of the ``STM32F407VxT6``.
+
+Core Peripherals
+----------------
+
+- ``SysTick``: Generating a 100us tick for the LCD routine and 1ms base system tick.
+- ``NVIC``: Interrupt controller
+- ``FPU``: The Flaoting Point Unit is activated and used in this formware.
+
+AHB Peripherals
+---------------
+
+- ``DMA2``
+	- ``Stream0``: DMA transfer of PT1000 measurement ADC to memory
+	- ``Stream4``: DMA transfer of Safety ADC measurement values
+	- ``Stream5``: Shell UART RX
+	- ``Stream7``: Shell UART TX
+- ``RNG``: Random number generation for stack corruption / overflow checker.
+- ``CRC``: CRC verfication of various data (Safety structures, EEPROM data, Safety RAM)
+- ``Backup RAM``: Backup RAM storing errors and bootloader information beyond system resets. The memory is cleared by a power cycle!
+
+ABP1 Peripherals
+----------------
+
+- ``IWDG``: Independent Watchdog
+- ``TIM2``: PT1000 measurement ADC sample time generation timer. Genewrates the 1 KHz sample trigger to the ADC peripheral via the internal event routing system.
+- ``TIM3``: PWM timer for oven relais output.
+- ``TIM5``: Input capture for rotary encoder.
+- ``TIM7``: Timer for loudspeaker tone generation.
+ 
+
+APB2 Peripherals
+----------------
+
+- ``SPI1``: SPI for external SPI-EEPROM
+- ``SDIO``: SD card interface
+- ``USART1``: Shell UART
+- ``ADC1``: Safety ADC for monitoring voltages
+- ``ADC3``: PT1000 measurement ADC