QDK PIC24/dsPIC-C30 - Quantum Leaps

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QDK PIC24/dsPIC-C30 www.state-machine.com/pic 6.2 The BSP header file bsp.h The BSP header file for the DPP application defines the desired ticking rate. This constant is useful for defining timeouts, which are always specified in units of clock ticks: #define BSP_TICKS_PER_SEC 100 void BSP_init(void); void BSP_displyPhilStat(uint8_t n, char const *stat); void BSP_busyDelay(void); /* to artificially extend RTC processing */ 6.3 BSP initialization The following BSP_init() function for the Explorer 16 board configures the DSP and peripherals as, shown in Listing 11. This file has been designed to be easily modifiable for other applications. Listing 11: The BSP_init() implementation in the bsp.c for the DPP example. void BSP_init(void) { RCONbits.SWDTEN = 0; /* disable Watchdog */ TRISA = 0x00; /* set LED pins as outputs */ PORTA = 0x00; /* set LEDs drive state low */ } if (QS_INIT((void *)0) == 0) { /* initialize the QS software tracing */ Q_ERROR(); } 6.4 Starting Interrupts in QF_onStartup() QP invokes the QF_onStartup() callback just before starting the background loop. The QF_onStartup() function must configure and start interrupts. At the minimum, QF_onStartup() must start the system clock tick interrupt. The following QF_onStartup() function enables the CPU Timer 0. void QF_onStartup(void) { /* entered with interrupts locked */ T2CON = 0; /* Use Internal Osc (Fcy), 16 bit mode, prescaler = 1 */ TMR2 = 0; /* Start counting from 0 and clear the prescaler count */ PR2 = BSP_TMR2_PERIOD - 1; /* set the timer period */ _T2IP = TIMER2_ISR_PRIO; /* set Timer 2 interrupt priority */ _T2IF = 0; /* clear the interrupt for Timer 2 */ _T2IE = 1; /* enable interrupt for Timer 2 */ T2CONbits.TON = 1; /* start Timer 2 */ } 6.5 Assertion Handling Policy in Q_onAssert() As described in Chapter 6 of [PSiCC2], all QP components use internally assertions to detect errors in the way application is using the QP services. You need to define how the application reacts in case of assertion failure by providing the callback function Q_onAssert(). Typically, you would put the system in Copyright © Quantum Leaps, LLC. All Rights Reserved. 28 of 35
QDK PIC24/dsPIC-C30 www.state-machine.com/pic a fail-safe state and try to reset. It is also a good idea to log some information as to where the assertion failed. The following code fragment shows the Q_onAssert() callback for PIC24/dsPIC. The function keeps locking interrupts in an endless loop. You can then break into the code with the debugger and inspect the cause of the assertion by backtracking the call stack. NOTE: This policy is only adequate for testing, but is not adequate for production release. void Q_onAssert(char const Q_ROM * const Q_ROM_VAR file, int line) { (void)file; /* avoid compiler warning */ (void)line; /* avoid compiler warning */ for (;;) { QF_INT_LOCK(dummy); /* make sure that interrupts are locked */ } } Copyright © Quantum Leaps, LLC. All Rights Reserved. 29 of 35
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