Hello,
Could you help to install the ST timer on the AT91Rm9200? I don't know how to setup the AIC registers correct. Maybe there are more than one big mistake.
void initialize_pit() { unsigned int flag, period, irq_id, mask, oldHandler, src_type, priority; volatile int status; void *newHandler; //period Timer0->ST_PIMR = period << 5; AT91F_ST_SetPeriodInterval(Timer0, period); //state //status = Timer0->ST_SR; //enable interrupt flag=1; Timer0->ST_IER = flag; AT91F_ST_EnableIt( Timer0, flag); //enable PMC AT91F_PMC_EnablePeriphClock(AT91C_BASE_PMC, 1 << AT91C_ID_IRQ0); //config AIC irq_id = 0; oldHandler = pAic->AIC_SVR[irq_id]; mask = 0x1 << irq_id; pAic->AIC_IDCR = mask ; pAic->AIC_SVR[irq_id] = (unsigned int) newHandler ; //* Store the Source Mode Register pAic->AIC_SMR[irq_id] = src_type | priority ; AT91F_AIC_ConfigureIt(pAic, irq_id, priority, src_type, newHandler); //enable AIC AT91F_AIC_EnableIt(pAic, 1); }
I hope somebody could help me with this problem...
best regards johannes
You still have uninitialized variables. Have you turned on all compiler warnings, and then made sure to clean out any warnings you get?
Another thing:
while(1) { while (tick == *(AT91C_ST_CRTR)); tick = *(AT91C_ST_CRTR); }
Notice 1: The semicolon at the end of the while() line menas that you have a while statement with an empty body - the indented second line isn't part of the while loop...
Notice 2: Is your loop intended as a delay? If all you want is the tick variable to be updated when the timer steps, you should let the interrupt service routine (ISR) assign a new value to tick on each interrupt. But then again - if the specific register in the timer is tha value you need, there is no reason to make a copy of it to a variable.
ok - now I get no warnings or errors... but the call for the ST_interrupt routine doesn't work...
void timer() { unsigned int pit_interval; // intveral pit timer initialize_usart1(); initialize_pit(); *(AT91C_ST_PIMR) = pit_interval; // value for the pit timer while(1) { //do nothing } }
The ST_SR register tell's me only if there has been a interrupt since if red it the last time..
irq_id = 1; priority = 1; src_type = 0x01; AT91F_AIC_ConfigureIt(pAic, irq_id, priority, src_type, ST_interrupt);
that is my configuration for the AIC.
No - the ST_SR is the direct cause for the ST interrupt line being asserted. There's a "hard-wired" connection on the chip that says "(ST_SR AND ST_IMR) -> Status of the ST interrupt line.
You can find #defined values for the source type and the priority in AT91RM9200_inc.h.
0x01 for the source type isn't even a valid value, since the source type field consists of bits 5 and 6 in the AIC_SMR.
I set the value for the src_type to 1.
but what's the reason, that my ST_interrupt(void) method never run?
Is the only solution to say if(ST_SR == 1) go to ST_interrupt(void) ?
johannes
AT91F_AIC_EnableIt(pAic, irq_id);
Where's the definition of pAic, and where does it get a value assigned to it ?
The src_type field consists of bits 5 and 6 of the AIC_SMRx. So valid values for src_type are 0x00, 0x20, 0x40 and 0x60.
Something's still wrong with your code.
No, that would just mess up things completely. The solution is getting the AIC and the ST programmed correctly. Maybe you need to recapitulate the appropriate chapters in the datasheet instead of trying to depend on others trying poke through code snippets and find out what exactly is wrong with your code. Maybe having another look inside a C textbook might be a good idea, too - might be a good idea judging from the use of uninitialized local variables.
AT91PS_AIC pAic = AT91C_BASE_AIC;
that's the definition for AIC
__inline unsigned int AT91F_AIC_ConfigureIt ( AT91PS_AIC pAic, // \arg pointer to the AIC registers unsigned int irq_id, // \arg interrupt number to initialize unsigned int priority, // \arg priority to give to the interrupt unsigned int src_type, // \arg activation and sense of activation void (*newHandler) (void) ) // \arg address of the interrupt handler { unsigned int oldHandler; unsigned int mask ; oldHandler = pAic->AIC_SVR[irq_id]; mask = 0x1 << irq_id ; //* Disable the interrupt on the interrupt controller pAic->AIC_IDCR = mask ; //* Save the interrupt handler routine pointer and the interrupt priority pAic->AIC_SVR[irq_id] = (unsigned int) newHandler ; //* Store the Source Mode Register pAic->AIC_SMR[irq_id] = src_type | priority ; //* Clear the interrupt on the interrupt controller pAic->AIC_ICCR = mask ; return oldHandler; }
irq_id = 1; priority = 1; src_type = 1; AT91F_AIC_ConfigureIt(pAic, irq_id, priority, src_type, ST_interrupt);
What do you think happen when you do:
priority = 1; src_type = 0x01;
and then:
AT91F_AIC_ConfigureIt(pAic, irq_id, priority,src_type, ST_interrupt);
Think about the line:
pAic->AIC_SMR[irq_id] = src_type | priority ;
With src_type = 1 and priority = 1, what use do you think that or operation makes? Are you spending any time trying to understand the answers you receive? What does the data sheet say about initializing the AIC_SMR register with the value 1?
Also, you may want to use the __irq keyword for the interrupt service routine (or use some other way to make sure the the interrupt service routine is compiled in ARM mode and not in THUMB mode. I do not know what setting uVision uses as a default. Interrupt service routines must always be in ARM mode, however).
The priority level can be between 0 (lowest) and 7 (highest).
so I select the value 1 for the priority - I don't see any disadvantages about it.
SCR_TYPE 0 0 high-level sensitive 0 1 positive edge-triggerd (is this not right to use this mode)?
0 1 are the bits 5 and 6 so it's 0x0000 0001 or not?
Or is this configuration false for the ST timer?
Very wrong. Look again at the data sheet. You are trying to store source type and priority in the same bits. Obviously that does not work. Have you read the data sheet? They normally very clearly shows what data is stored in the different bits of a register.
Also, Christoph Franck have already written in an earlier post what values you may use for the source type. I can't see how you can manage to call the least significant bit "bit 5" or "bit 6".
You just posted the piece of code that provides the answer to the question:
There is nothing in here that shifts src_type 5 bit positions to the left, is there ?
Also, you may want to work with the #define constants in the #include file instead of numeric values:
#define AT91C_AIC_SRCTYPE (0x3 << 5) // (AIC) Interrupt Source Type #define AT91C_AIC_SRCTYPE_INT_LEVEL_SENSITIVE (0x0 << 5) // (AIC) Internal Sources Code Label Level Sensitive #define AT91C_AIC_SRCTYPE_INT_EDGE_TRIGGERED (0x1 << 5) // (AIC) Internal Sources Code Label Edge triggered #define AT91C_AIC_SRCTYPE_EXT_HIGH_LEVEL (0x2 << 5) // (AIC) External Sources Code Label High-level Sensitive #define AT91C_AIC_SRCTYPE_EXT_POSITIVE_EDGE (0x3 << 5) // (AIC) External Sources Code Label Positive Edge triggered
thanks for the hint...
void initialize_st() { unsigned int flag, period, irq_id, priority; Timer0 = AT91C_BASE_ST; /* Base Address for the ST Timer */ //period for the pit timer period = 1; AT91F_ST_SetPeriodInterval(Timer0, period); // enable interrupts flag=1; AT91F_ST_EnableIt( Timer0, flag); //config AIC irq_id = 1; priority = 1; AT91F_AIC_ConfigureIt(pAic, irq_id, priority, AT91C_AIC_SRCTYPE_INT_EDGE_TRIGGERED, ST_interrupt); //enable AIC AT91F_AIC_EnableIt(pAic, irq_id); }
I don't work - I think there are many other mistakes in my code...
__irq keyword for the interrupt service routine?
do you mean I have to use this for the interrupt routine?
void ST_interrupt(void) { AT91F_US_PutChar (COM1_1,'u'); while( !(COM1_1->US_CSR & AT91C_US_TXRDY) ) continue; }
Could you explain it a little bit for me?
AT91F_AIC_ConfigureIt(pAic, irq_id, priority, AT91C_AIC_SRCTYPE_INT_EDGE_TRIGGERED, ST_interrupt);
As I mentioned earlier, you probably want the interrupt to be level-triggered, not edge-triggered. If the interrupt line was high before you enabled the interrupt, the AIC will never see an edge and hence never call your interrupt service routine.
You will also need to read ST_SR somewhere in your interrupt routine in order to clear the interrupt. One way of doing this is doing something along the lines of AIC_EOICR = ST_SR, which both reads ST_SR (clearing the ST interrupt) and writes to AIC_EOICR (telling the AIC that the interrupt service routine has finished).
thank for your answer...
AT91PS_ST pST = AT91C_BASE_ST; void ST_interrupt(void) { volatile int status; //clear ST_SR status = pST->ST_SR; AT91F_US_PutChar (COM1_1,'u'); while( !(COM1_1->US_CSR & AT91C_US_TXRDY) ) continue; // Here acknowledge the end of interrupt AT91C_BASE_AIC->AIC_EOICR = 0x0; }
and I changed the value
irq_id = 1; priority = 1; AT91F_AIC_ConfigureIt(pAic, irq_id, priority, AT91C_AIC_SRCTYPE_INT_LEVEL_SENSITIVE, ST_interrupt);
AT91PS_ST Timer0; /* Variable (pointer) Timer0 für die Struct AT91S_ST definieren */ AT91PS_AIC pAic = AT91C_BASE_AIC; AT91PS_ST pST = AT91C_BASE_ST; void ST_interrupt(void) { volatile int status; //clear ST_SR status = pST->ST_SR; AT91F_US_PutChar (COM1_1,'u'); while( !(COM1_1->US_CSR & AT91C_US_TXRDY) ) continue; // Here acknowledge the end of interrupt AT91C_BASE_AIC->AIC_EOICR = 0x0; } void initialize_st() { unsigned int flag, period, irq_id, priority; Timer0 = AT91C_BASE_ST; /* Base Address for the ST Timer */ //period for the pit timer period = 1; AT91F_ST_SetPeriodInterval(Timer0, period); // enable interrupts flag=1; AT91F_ST_EnableIt( Timer0, flag); //config AIC irq_id = 1; priority = 1; AT91F_AIC_ConfigureIt(pAic, irq_id, priority, AT91C_AIC_SRCTYPE_INT_LEVEL_SENSITIVE, ST_interrupt); //enable AIC AT91F_AIC_EnableIt(pAic, irq_id); } void timer() { unsigned int st_interval; // intveral st timer initialize_usart1(); initialize_st(); *(AT91C_ST_PIMR) = st_interval; // value for the st timer while(1) { } }
Is there another stupid mistake in this code - because it doesn't work...