QDK PIC24/dsPIC-XC16 - Quantum Leaps

QDK
PIC24/dsPIC-XC16
www.state-machine.com/pic
7.2 QS Trace Output in QF_onIdle()/QK_onIdle()
To be minimally intrusive, the actual output of the QS trace data happens when the system has nothing
else to do, that is, during the idle processing. The following code snippet shows the code placed either in
the QF_onIdle() callback (“Vanilla” port), or QK_onIdle() callback (in the QK port):
Listing 13: QS trace output using the UART on the PIC24FJ CPU
#define UART_TXFIFO_DEPTH 16
. . .
void QK_onIdle(void) {
. . .
#ifdef Q_SPY
(1) while (U2STAbits.UTXBF == 0U) { /* TX Buffer not full */
uint16_t b;
(2) QF_INT_LOCK(dummy);
(3) b = QS_getByte();
(4) QF_INT_UNLOCK(dummy);
(5) if (b == QS_EOD) { /* End-Of-Data reached */
(6) break; /* break out of the loop */
}
(7) U2TXREG = (uint8_t)b; /* stick the byte to TXREG for transmission */
}
#elif defined NDEBUG
__asm__ volatile("disi #0x0001");
Idle(); /* transition to Idle mode, see NOTE03 */
#else
QF_INT_UNLOCK(dummy); /* unlock interrupts, see NOTE01 */
#endif
}
(1) As long as the UTXBF (TX buffer full) flag is not set, the UART2 TX can accept new bytes.
(2) Interrupts are locked to call QS_getByte().
(3) The function QS_getByte() returns the next byte or QS_EOD (end-of-data) if the QS ring buffer is
empty.
(4) The interrupts are unlocked after the call to QS_getByte().
(5-6) If end-of-data is reached the loop is terminated for this invocation of QK_onIdle().
(7) The byte obtained from the QS buffer is inserted into the UART2 transmit register for transmission.
7.3 Invoking the QSpy Host Application
The QSPY host application receives the QS trace data, parses it and displays on the host workstation
(currently Windows or Linux). For the configuration options chosen in this port, you invoke the QSPY host
application as follows (please refer to “QSP Reference Manual” section in the “QP/C Reference Manual”
an also to Chapter 11 in [PSiCC2]):
qspy –cCOM1 –b38400 –O2 –F2 –S1 –E1 –Q1 –P1 –B1
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