Timer.c Check for prescaler overflow and wrote some documentation with new todo s

README.md

@@ -20,14 +20,15 @@ INTERFACES
 	- pin
 		- pin.h Is now only missing interrupt functions 
  	- USART
-		- usart.h Is wirking Great But there are many more functionalities to be added.
+		- usart.h Is working Great But there are many more functionalities to be added.
 		- usart.h Interrupt and DMA are the next steps
 
 	- deviceSetup	
 		- deviceSetup.h it's a copy of what ST has made but wit direct register acsess
 		- deviceSetup.h we need to test it with other configurations to see if it works as 
 			supposed or if the MCU is on it's defaul 8MHz congif. 
-		- setupInit(); funtion is called from bsl/csl/stm32f042/startup/startup_stm32f042x6.s and is called before the main(); 
+		- setupInit(); funtion is called from bsl/csl/stm32f042/startup/startup_stm32f042x6.s 
+			and is called before the main(); 
 
 PROGRAMMING 
 	

bsl/csl/interfaces/timer.h

@@ -10,8 +10,11 @@
 * **Detailed Description :**
 * This the timer interface and belongs to the interface layer
 *
-* @todo 
-*	- 19.12.2021 : Should we check for a 32 to 16 bit overflow situation.  
+* @todo Following functions are to be implmented : 
+* timerSetHz
+* timerSetMs
+* timerSetNs
+* timerSetPs
 **************************************************************************************************
 */
 
@@ -24,9 +27,11 @@ extern "C" {
 
 #include "hardwareDescription.h"
 
+
+/*! Emun of possible Timer Errors */ 
 typedef enum {
-	functionNotSupported,
-	prescalerOutOfRange
+	functionNotSupported,	/*!< This Funtion is not awailable on this **HARDWARE** */
+	prescalerOutOfRange		/*!< Set prescaler value exeeds the Register's **HARDWARE** size */
 } timerError_t;
 
 typedef enum {
@@ -41,12 +46,21 @@ typedef enum {
 	onePulse
 } timerMode_t;
 
+/*! 
+ * Reset the timer to its default state.
+ */
 void timerReset(timerNo_t timer);
 void timerActivateBus(timerNo_t timer); 
 void timerEnable(timerNo_t timer); 
 void timerDisable(timerNo_t timer);
 void timerSetMode(timerNo_t timer, timerMode_t mode); 
 void timerSetCountDirection(timerNo_t timer, timerCountDirection_t direction); 
+
+/*! 
+ * Sets the given timer's prescaler value. 
+ * This fucntion will also check if the entered prascaler value exeeds the register size.
+ * If violated the prescalerOutOfRange Error will be generated. 
+ */
 void timerSetPrescaler(timerNo_t timer, uint32_t prescaler); 
 void timerSetPostscaler(timerNo_t timer, uint32_t postscaler); 
 void timerSetAutoReload(timerNo_t timer, uint32_t reload); 
@@ -56,6 +70,7 @@ void timerClearCounter(timerNo_t timer);
 
 /* Second stage configuration */
 void timerInit(timerNo_t timer, uint32_t prescaler, uint32_t period, timerCountDirection_t direction, timerMode_t mode);
+
 void timerSetHz(timerNo_t timer, uint16_t hz); 
 void timerSetMs(timerNo_t timer, uint16_t ms); 
 void timerSetNs(timerNo_t timer, uint16_t ns); 

bsl/csl/stm32f042/Device/hardwareDescription.h

@@ -194,6 +194,9 @@ static const uint8_t timerBus_En_bitPos[MAX_TIMER_CHANNEL_COUNT] = {
 	RCC_APB2ENR_TIM17EN_Pos
 };
 
+/*!
+ *	RCC timer Reset Bit Position list
+ * */
 static const uint8_t timerBus_Rst_bitPos[MAX_TIMER_CHANNEL_COUNT] = {
 	RCC_APB2RSTR_TIM1RST_Pos,
 	RCC_APB1RSTR_TIM2RST_Pos,
@@ -203,13 +206,28 @@ static const uint8_t timerBus_Rst_bitPos[MAX_TIMER_CHANNEL_COUNT] = {
 	RCC_APB2RSTR_TIM17RST_Pos
 };
 
+/*!
+ *	RCC Bus number index list connected to the timer 
+ * */
 static const uint8_t timerBus_No[MAX_TIMER_CHANNEL_COUNT] = {
-	2,
-	1,
-	1,
-	1,
-	2,
-	2
+	2, /*!< timer 1 is connected to bus 2 */
+	1, /*!< timer 2 is connected to bus 1 */
+	1, /*!< timer 3 is connected to bus 1 */
+	1, /*!< timer 14 is connected to bus 1 */
+	2, /*!< timer 16 is connected to bus 2 */
+	2  /*!< timer 17 is connected to bus 2 */
+};
+
+/*! 
+ * Timer Prescaler resolution list TO BE DELETED IF NOT NEEDED
+ * */
+static const  uint32_t timerRes_Prescaler[MAX_TIMER_CHANNEL_COUNT] = {
+	0xFFFF, /*!< Timer 1 Prescaler Max Value */ 
+	0xFFFF, /*!< Timer 2 Prescaler Max Value */ 
+	0xFFFF, /*!< Timer 3 Prescaler Max Value */ 
+	0xFFFF, /*!< Timer 14 Prescaler Max Value */ 
+	0xFFFF, /*!< Timer 16 Prescaler Max Value */ 
+	0xFFFF, /*!< Timer 17 Prescaler Max Value */ 
 };
 
 #ifdef __cplusplus

bsl/csl/stm32f042/Src/timer.c

@@ -54,12 +54,17 @@ void timerSetCountDirection(timerNo_t timer, timerCountDirection_t direction)
  
 void timerSetPrescaler(timerNo_t timer, uint32_t prescaler)
 {
+	if(prescaler > timerRes_Prescaler[timer])
+	{
+		timerThrowError(prescalerOutOfRange);
+		return; // To prevent writing wrong value in to the Register
+	}
 	BASE->PSC = prescaler;
 }
  
 void timerSetPostscaler(timerNo_t timer, uint32_t postscaler)
 {
-	
+	timerThrowError(functionNotSupported);
 }
  
 void timerSetAutoReload(timerNo_t timer, uint32_t reload)
@@ -138,7 +143,6 @@ void timerSetPs(timerNo_t timer, uint16_t ps)
 	
 }
  
-
 void timerSart(timerNo_t timer)
 {
 	timerEnable(timer);
@@ -163,6 +167,6 @@ uint32_t timerGetCount(timerNo_t timer)
 
 void timerThrowError(timerError_t error)
 {
-	
+	while(1);	
 }
  

main.cpp

@@ -1,6 +1,3 @@
-#warning "Generated from: " __FILE__
-
-
 #include "main.hpp"
 #include "delay.h"
 #include "deviceSetup.h"
@@ -11,14 +8,11 @@
 int main(int argc, char *argv[])
 {
 	uint8_t i = 0; 
-	uint8_t a = '0';
-
-	delayInitMs(8000000, 1000); 
 
-	//timerSetHz(timer_2,3);
+	delayInitMs(8000000, 1000); // Clock Freq and Divider for ARM library 
 
-	timerInit(timer_2, 7999, 999, downCounting, counter); 
-	timerSart(timer_2);
+	timerInit(timer_1, 7999, 999, downCounting, counter); 
+	timerSart(timer_1);
 	
 	pinConfig(pinB3, output, pushPull, def_res, def_speed);
 	pinConfig(pinA0, input, def_stage, pullDown, def_speed);	
@@ -33,7 +27,7 @@ int main(int argc, char *argv[])
 				noFlowControl); 
 
 	//clears screen and send the wellcome messgae
-//	print_Usart(usart2, ASCII_clear); 
+	print_Usart(usart2, ASCII_clear); 
 	print_Usart(usart2, const_cast<char *>("Wellcome to our KED project\n\r")); 
 	
 
@@ -54,22 +48,6 @@ int main(int argc, char *argv[])
 		pinToggle(pinB3);
 	}
 	
-	/*
-	while(1)
-	{
-		//USART will rteturn what wou type and trun led on if you press "1"
-		a =	usartGetChar(usart2); 
-		usartSendChar(usart2, a);
-
-		if(a == '1') {
-			pinWrite(pinB3,1);
-		} else if(a == '0'){
-			pinWrite(pinB3,0);
-		
-		delayMs(100); 
-	}
-	*/
-
 	return 1;
 }