Hi Venu, > I'm using COSMIC compiler(an excellent one). > For ICC12 Good to know. I have used both ICC12 and Metrowerks (which I am using now), so I am familiar with their standards for interrupts. > I use Tx interrupt for Internal Data acqusition of h/w with Tx1 and > Tx2 and other messages will use Tx0 (without any Tx interrupt). Reserving one register for non-interrupt messages is a good idea. In the past (with serial buses) I have used a message queuing scheme with priority bits to assure that time-critical messages get sent first. It works well, but in high bandwidth situations it's possible that the low priority message may wait a long time. Of course, depending on the priority of the Tx0 message, the CAN controller might hold it for quite a while in a similar situation. I look forward to playing with these ideas. Thanks again for your very generous assistance. Regards, Paul

about 1): to mark as interrupt, you can use for HIWARE/Metrowerks either a pragma or the interrupt keyword: #pragma TRAP_PROC void myISR(void) {.... or interrupt void MyISR(void) {... optionally you can specify the vector number with the interrupt keyword (so you do not need to adapt/edit the linker command file: interrupt 0 void MyResetISR(void) {... Erich > -----Original Message----- > From: Paul Johnson [mailto:] > Sent: Thursday, August 15, 2002 7:36 PM > To: > Subject: RE: [68HC12] Re: Interrupt driven MsCan bus > Venu, > > You have been very generous with your information. Thank you very much. > > I have two more quick questions. > > 1. What compiler are you using? I don't recognize the @interrupt form from > either HIWARE or ICC12. > > 2. In you transmit interrupt, do you use all three output buffers or just > the first one? I assume that transmission would be much more efficient if > all three buffers are used. > > Thanks again for the great kick-start. > > Best regards, > > Paul > > > -----Original Message----- > > From: kp_venu [mailto:] > > Sent: Tuesday, August 13, 2002 8:37 PM > > To: > > Subject: [68HC12] Re: Interrupt driven MsCan bus > > > > > > Paul, > > Yes. It's related to SYNCH bit in CMCR0 register. > > Synchronisation is done at end of initialisation routine. > > Regards, > > Venu > > void CanInit(void) // CAN initialisation routine > > { > > CMCR0 |= SFTRES; // place MSCAN12 in soft reset mode > > > > // CMCR1 = 1; // MSCAN12 clock = 2(ECLK) > > // 250kbps = 0xC3, 500kpbs = > > 0xC1; > > CBTR0 = BTR0; // Synchronisation jump width = 4Tq clock > > cycles > > // SJW1,SJw0 = 11 = C0h > > // Baud rate = > > 500Kbs,prescaler=4 0011 = 03h > > CBTR1 = BTR1; // SAMP = 0; one sample per bit > > // Time Segment 1 = 10Tq > > clock cycles = 1001= 9h > > // Time segment 2 = 5 Tq > > clock cycles = 0100= 4h > > CTCR = 0; // clear transmitt control register > > > > CIDAC = 0x17; // four 16-bit Acceptance Filters > > > > FilterConfig(); // Acceptance Filter configuarion for PM-ECU > > // located in ECU Configuration file > > CMCR0 &= ~(SFTRES); // take MSCAN12 out of soft reset > > CRFLG = 0xFF; // Clear all CAN error flags > > CRIER = BOFFIE | OVRIE | RXFIE; // Enable interrupts for > > Error and receive flags > > while(!(CMCR0 & SYNCH)){}; //wait for synchronisation with > > CAN bus > > } > > > -------------------- > > ">http://docs.yahoo.com/info/terms/

Paul, I'm using COSMIC compiler(an excellent one). For ICC12, #pragma interrupt_handler MyInterrupthandler no idea about HIWARE. I use Tx interrupt for Internal Data acqusition of h/w with Tx1 and Tx2 and other messages will use Tx0 (without any Tx interrupt). Regards, Venu --- In 68HC12@y..., "Paul Johnson" <paul@l...> wrote: > Venu, > > You have been very generous with your information. Thank you very much. > > I have two more quick questions. > > 1. What compiler are you using? I don't recognize the @interrupt form from > either HIWARE or ICC12. > > 2. In you transmit interrupt, do you use all three output buffers or just > the first one? I assume that transmission would be much more efficient if > all three buffers are used. > > Thanks again for the great kick-start. > > Best regards, > > Paul >

Hi! Hiware interrupts: a vector definition in prm-file VECTOR ADDRESS 0xffc6 Can_RxIntHandler /* MSCAN 0 Receive */ and a handler function (use '#pragma TRAP_PROC' instead of '@interrupt') #pragma TRAP_PROC void CANRxIntHandler() { ... } JK -----Original Message----- From: Paul Johnson [mailto:] Sent: 13. elokuuta 2002 0:53 To: Subject: [68HC12] Interrupt driven MsCan bus Hi All, All of the examples I have seen using the CAN bus with the HC12 line uses simple polling. Is anyone aware of an example using interrupts? Has anyone out there used interrupts themselves? On a related note, all of the examples use only one of the output registers, but in an interrupt routine I would assume that you would use any open register, no? Does anyone have any experience with this? Thanks, Paul -------------------- ">http://docs.yahoo.com/info/terms/

Venu, You have been very generous with your information. Thank you very much. I have two more quick questions. 1. What compiler are you using? I don't recognize the @interrupt form from either HIWARE or ICC12. 2. In you transmit interrupt, do you use all three output buffers or just the first one? I assume that transmission would be much more efficient if all three buffers are used. Thanks again for the great kick-start. Best regards, Paul > -----Original Message----- > From: kp_venu [mailto:] > Sent: Tuesday, August 13, 2002 8:37 PM > To: > Subject: [68HC12] Re: Interrupt driven MsCan bus > Paul, > Yes. It's related to SYNCH bit in CMCR0 register. > Synchronisation is done at end of initialisation routine. > Regards, > Venu > void CanInit(void) // CAN initialisation routine > { > CMCR0 |= SFTRES; // place MSCAN12 in soft reset mode > > // CMCR1 = 1; // MSCAN12 clock = 2(ECLK) > // 250kbps = 0xC3, 500kpbs = > 0xC1; > CBTR0 = BTR0; // Synchronisation jump width = 4Tq clock > cycles > // SJW1,SJw0 = 11 = C0h > // Baud rate = > 500Kbs,prescaler=4 0011 = 03h > CBTR1 = BTR1; // SAMP = 0; one sample per bit > // Time Segment 1 = 10Tq > clock cycles = 1001= 9h > // Time segment 2 = 5 Tq > clock cycles = 0100= 4h > CTCR = 0; // clear transmitt control register > > CIDAC = 0x17; // four 16-bit Acceptance Filters > > FilterConfig(); // Acceptance Filter configuarion for PM-ECU > // located in ECU Configuration file > CMCR0 &= ~(SFTRES); // take MSCAN12 out of soft reset > CRFLG = 0xFF; // Clear all CAN error flags > CRIER = BOFFIE | OVRIE | RXFIE; // Enable interrupts for > Error and receive flags > while(!(CMCR0 & SYNCH)){}; //wait for synchronisation with > CAN bus > } >

Paul, Yes. It's related to SYNCH bit in CMCR0 register. Synchronisation is done at end of initialisation routine. Regards, Venu void CanInit(void) // CAN initialisation routine { CMCR0 |= SFTRES; // place MSCAN12 in soft reset mode // CMCR1 = 1; // MSCAN12 clock = 2(ECLK) // 250kbps = 0xC3, 500kpbs = 0xC1; CBTR0 = BTR0; // Synchronisation jump width = 4Tq clock cycles // SJW1,SJw0 = 11 = C0h // Baud rate = 500Kbs,prescaler=4 0011 = 03h CBTR1 = BTR1; // SAMP = 0; one sample per bit // Time Segment 1 = 10Tq clock cycles = 1001= 9h // Time segment 2 = 5 Tq clock cycles = 0100= 4h CTCR = 0; // clear transmitt control register CIDAC = 0x17; // four 16-bit Acceptance Filters FilterConfig(); // Acceptance Filter configuarion for PM-ECU // located in ECU Configuration file CMCR0 &= ~(SFTRES); // take MSCAN12 out of soft reset CRFLG = 0xFF; // Clear all CAN error flags CRIER = BOFFIE | OVRIE | RXFIE; // Enable interrupts for Error and receive flags while(!(CMCR0 & SYNCH)){}; //wait for synchronisation with CAN bus } --- In 68HC12@y..., "Paul Johnson" <paul@l...> wrote: > Hi Venu, > > Thanks for this example, it's very helpful. You made one comment that > intrigues me when you talked about using polling for synchronization. > > Do I understand that to mean that you wake up with interrupts off, us > polling on all devices to establish who's out there, etc., then switch to > interrupt mode? Is this related to the SYNCH bit in the CMCR0 register? I > do not really know how to use this bit. Sometimes, if I wait for it to go > high, it never does. If I just ignore it polling seems to work anyway. > Sometimes if I wait for it to go hi it does. I have not been able to > determine what makes this bit change. > > If you have some pointer on synchronization, I would be most appreciative. > > Thanks, > > Paul > > > -----Original Message----- > > From: kp_venu [mailto:kp_venu@y...] > > Sent: Monday, August 12, 2002 9:19 PM > > To: 68HC12@y... > > Subject: [68HC12] Re: Interrupt driven MsCan bus > > > > > > Hi, > > I always use Rx and Tx interrupts for msCAN. > > I never used polling except for synchronization. > > Regards, > > Venu > > > > @interrupt void CANRxhandler(void) // CAN Receive interrupt handler > > { > > char Filter; // temprory variable > > CH_INT CAN_RxBuff; // temp variable for CAN ID storage > > CAN_RxBuff.INT = RBUF[0] << 8 | RBUF[1];// save CAN ID from > > Rx buffers > > CANid = ((CAN_RxBuff.INT & CAN_ID_MASK_2A) >> 5);// allign ID > > bits > > Filter = CIDAC & 0x0F; // get filter value > > if(Filter == 0x01) // filter 1 > > { > > switch(CANid) > > { > > case 0: // ID - 700 > > CanDaqBusy(); // CAN-DAQ busy message > > break; > > case 1: // ID - 701 > > CanDaqReady(); // CAN-DAQ ready message > > break; > > case 2: // ID - 702 > > EnableIntDaq(); // Enable Internal Data acquisition > > break; > > } > > } > > if(Filter == 0x02) // filter 2 > > { > > // your code > > } > > if(Filter == 0x03) // filter 3 > > { > > // your code > > } > > CRFLG = RXF; // clear RXF flag > > } > > > > --- In 68HC12@y..., "Paul Johnson" <paul@l...> wrote: > > > Hi All, > > > > > > All of the examples I have seen using the CAN bus with the HC12 > > line uses > > > simple polling. Is anyone aware of an example using interrupts? > > Has anyone > > > out there used interrupts themselves? > > > > > > On a related note, all of the examples use only one of the output > > registers, > > > but in an interrupt routine I would assume that you would use any > > open > > > register, no? Does anyone have any experience with this? > > > > > > Thanks, > > > > > > Paul > > > > > > > > -------------------- > > > > > > > > ">http://docs.yahoo.com/info/terms/ > > > > > >

Hi Venu, Thanks for this example, it's very helpful. You made one comment that intrigues me when you talked about using polling for synchronization. Do I understand that to mean that you wake up with interrupts off, us polling on all devices to establish who's out there, etc., then switch to interrupt mode? Is this related to the SYNCH bit in the CMCR0 register? I do not really know how to use this bit. Sometimes, if I wait for it to go high, it never does. If I just ignore it polling seems to work anyway. Sometimes if I wait for it to go hi it does. I have not been able to determine what makes this bit change. If you have some pointer on synchronization, I would be most appreciative. Thanks, Paul > -----Original Message----- > From: kp_venu [mailto:] > Sent: Monday, August 12, 2002 9:19 PM > To: > Subject: [68HC12] Re: Interrupt driven MsCan bus > Hi, > I always use Rx and Tx interrupts for msCAN. > I never used polling except for synchronization. > Regards, > Venu > > @interrupt void CANRxhandler(void) // CAN Receive interrupt handler > { > char Filter; // temprory variable > CH_INT CAN_RxBuff; // temp variable for CAN ID storage > CAN_RxBuff.INT = RBUF[0] << 8 | RBUF[1];// save CAN ID from > Rx buffers > CANid = ((CAN_RxBuff.INT & CAN_ID_MASK_2A) >> 5);// allign ID > bits > Filter = CIDAC & 0x0F; // get filter value > if(Filter == 0x01) // filter 1 > { > switch(CANid) > { > case 0: // ID - 700 > CanDaqBusy(); // CAN-DAQ busy message > break; > case 1: // ID - 701 > CanDaqReady(); // CAN-DAQ ready message > break; > case 2: // ID - 702 > EnableIntDaq(); // Enable Internal Data acquisition > break; > } > } > if(Filter == 0x02) // filter 2 > { > // your code > } > if(Filter == 0x03) // filter 3 > { > // your code > } > CRFLG = RXF; // clear RXF flag > } > > --- In 68HC12@y..., "Paul Johnson" <paul@l...> wrote: > > Hi All, > > > > All of the examples I have seen using the CAN bus with the HC12 > line uses > > simple polling. Is anyone aware of an example using interrupts? > Has anyone > > out there used interrupts themselves? > > > > On a related note, all of the examples use only one of the output > registers, > > but in an interrupt routine I would assume that you would use any > open > > register, no? Does anyone have any experience with this? > > > > Thanks, > > > > Paul > > -------------------- > > ">http://docs.yahoo.com/info/terms/ >

Hi, I always use Rx and Tx interrupts for msCAN. I never used polling except for synchronization. Regards, Venu @interrupt void CANRxhandler(void) // CAN Receive interrupt handler { char Filter; // temprory variable CH_INT CAN_RxBuff; // temp variable for CAN ID storage CAN_RxBuff.INT = RBUF[0] << 8 | RBUF[1];// save CAN ID from Rx buffers CANid = ((CAN_RxBuff.INT & CAN_ID_MASK_2A) >> 5);// allign ID bits Filter = CIDAC & 0x0F; // get filter value if(Filter == 0x01) // filter 1 { switch(CANid) { case 0: // ID - 700 CanDaqBusy(); // CAN-DAQ busy message break; case 1: // ID - 701 CanDaqReady(); // CAN-DAQ ready message break; case 2: // ID - 702 EnableIntDaq(); // Enable Internal Data acquisition break; } } if(Filter == 0x02) // filter 2 { // your code } if(Filter == 0x03) // filter 3 { // your code } CRFLG = RXF; // clear RXF flag } --- In 68HC12@y..., "Paul Johnson" <paul@l...> wrote: > Hi All, > > All of the examples I have seen using the CAN bus with the HC12 line uses > simple polling. Is anyone aware of an example using interrupts? Has anyone > out there used interrupts themselves? > > On a related note, all of the examples use only one of the output registers, > but in an interrupt routine I would assume that you would use any open > register, no? Does anyone have any experience with this? > > Thanks, > > Paul