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QDK™

Renesas RX with HEW

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NOTE: The extended QK scheduler is used, instead of the regular scheduler, to save and restore the

FPSW

QK_EXT_SAVE()

QK_EXT_RESTORE()

specify how to save

and restore the extended context of the

FPSW

(14) The RX Accumulator register is restored.

(15) The

QK_EXT_SAVE()

macro specifies the process of saving the extended context, which in the case

of the RX processor is the FPSW register.

(16) The Renesas built-in function

get_fpsw()

resolves to a single instruction “

MVFC Rn

”.

(17) The

QK_EXT_RESTORE()

macro specifies the process of restoring the extended context, which in the

case of the RX processor is the FPSW register.

(18) The Renesas built-in function

set_fpsw()

resolves to a single instruction “

MVTC Rn

”.

5.4 The Board Support Package for the QK Port

The BSP for the QK version is located in the file

bsp.c

in the directory

qpc\examples\rx\qk\renesas\dpp-qk-yrdkrx62n\

. The BSP for QK is mostly similar to the “Vanilla”

kernel discussed before. This section describes only the differences between the two kernels.

5.4.1 Interrupt Service Routines (ISRs) for the preemptive QK kernel

As mentioned earlier, the Renesas compiler enables the user to write ISRs as interrupt functions in C/C+

+. These compiler-generated ISRs are perfectly adequate for the preemptive kernel

Listing 12: Tick timer ISR for QK in intprg.c

(1) #include "vect.h"

#pragma section IntPRG

. . .

(2) void Excep_CMTU0_CMT0(void) {

(3) QK_ISR_ENTRY(); /* inform the QK kernel about entering the ISR */

#ifdef Q_SPY

l_tickTime_ += l_tickPeriod_; /* account for the clock rollover */

#endif

QF_TICK(&l_tickISR); /* process all armed time events */

(4) QK_ISR_EXIT(); /* inform the QK kernel about exiting the ISR */

}

(1) The header file

vect.h

provides declarations of all possible interrupt functions.

(2) The ISR must be one of the

#pragma interrupt

functions declared in the

vect.h

header file.

(3) The macro

QK_ISR_ENTRY()

informs the QK kernel that the ISR has been entered. It must be

called before invoking any QP services in the ISR body.

(4) The macro

QK_ISR_EXIT()

informs the QK kernel that the ISR is about to be exited. It must be

called at the very end of the ISR body.

NOTE: The macros

QK_ISR_ENTRY()

and

QK_ISR_EXIT()

save and restore the RX Accumlator

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