alan
Joined: 12 Nov 2012
Posts: 357
Location: South Africa
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| [SOLVED] PTG as source to start ADC conversion |
 Posted: Fri May 09, 2014 4:46 am |
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Goodday
dsPIC33EP32MC202
CCS 5.024
Anybody have any experience setting the PTG up.
If I debug the target with MPLABX and ICD3 it seems that the PTG are stepping by looking at the PTGQPTR, but I do not get the start to the ADC.
Here are code snippets to set up and program.
Routine to write to the PTG queue. All variables that start with __ have the format #word __PTGCST = getenv("SFR:PTGCST") //PTG Control/Status register
| Code: |
#define PTGCTRL (0x0 << 0)
#define PTGWHI (0x4 << 4)
#define PTGTRIG (0x8 << 4)
#define PTGJMP (0xA << 4)
#define PTGJMPC0 (0xC << 4)
#define PTGIRQ (0x7 << 4)
void Write_PTG_Step(uint8_t command) {
switch (__STEP_Counter) {
case 0: __PTGQUE0 = command; break;
case 1: __PTGQUE0 |= (command<<8); break;
case 2: __PTGQUE1 = command; break;
case 3: __PTGQUE1 |= (command<<8); break;
case 4: __PTGQUE2 = command; break;
case 5: __PTGQUE2 |= (command<<8); break;
case 6: __PTGQUE3 = command; break;
case 7: __PTGQUE3 |= (command<<8); break;
case 8: __PTGQUE4 = command; break;
case 9: __PTGQUE4 |= (command<<8); break;
case 10: __PTGQUE5 = command; break;
case 11: __PTGQUE5 |= (command<<8); break;
case 12: __PTGQUE6 = command; break;
case 13: __PTGQUE6 |= (command<<8); break;
case 14: __PTGQUE7 = command; break;
case 15: __PTGQUE7 |= (command<<8); break;
}
__STEP_Counter++;
}
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Routine that get's called once from main()
| Code: |
uint8_t __STEP_Counter;
void Periodic_ADC() {
__PTGCST = 0x0000; //Disable Module
__STEP_Counter = 0; //Reset commands in PTG Queue to 0
__PTGQPTR = 0;
__PTGCON = 0x3F00; //Clock source are Fosc and divide by 32
__PTGBTE = 0x8000;//With broadcast trig will assert PTGO15 which is for ADC trig
__PTGT1LIM = 0xF424; //25ms Timer when called
//Write STEPS to Buffer
Write_PTG_Step(PTGTRIG | 0x0f); //Send a PTGO15 trig which are one for the ADC
Write_PTG_Step(PTGCTRL | 9); //Start and wait for the PTG Timer1 to match
Write_PTG_Step(PTGTRIG | 0x0f); //Send a PTGO15 trig which are one for the ADC
Write_PTG_Step(PTGCTRL | 9); //Start and wait for the PTG Timer1 to match
Write_PTG_Step(PTGCTRL | 9); //Start and wait for the PTG Timer1 to match
Write_PTG_Step(PTGCTRL | 0x0f); //Send a broadcast trigger PTGBTE
Write_PTG_Step(PTGCTRL | 9); //Start and wait for the PTG Timer1 to match
Write_PTG_Step(PTGCTRL | 9); //Start and wait for the PTG Timer1 to match
Write_PTG_Step(PTGCTRL | 9); //Start and wait for the PTG Timer1 to match
//the PTGT1LIM register
Write_PTG_Step(PTGJMP | 0); //Jump back to STEP0
__PTGCST = 0x8000;
__PTGCST = 0x8080;
} |
This is the ADC setup. I had to manipulate the registers as I can't find a option in CCS to set the trigger to PTGO15
Frequency is set as 80MHz with FRC
| Code: |
setup_adc(ADC_CLOCK_DIV_2);
setup_adc_ports(sAN0 | sAN1, VSS_VDD );
set_adc_channel(0);
//Setup ADC to allow for PTG trig
AD1CON1 &= 0x7f0f; //Switch module off and reset sample clock select bits
AD1CON1 |= 0x00D0; //PTGO15 primary trigger to start conversion
AD1CON3 &= 0x00ff;
AD1CON1 |= 0x8000; //Switch module on
enable_interrupts(INT_ADC1);
enable_interrupts(INT_SPI1);
enable_interrupts(INTR_GLOBAL);
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and finally
| Code: |
#INT_ADC1
void adc_ready(void) {
VTemp = read_adc(ADC_READ_ONLY);
output_toggle(LED);
}
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EDIT:
Needed to set the ASAM: ADC Sample Auto-Start as well thus
| Code: |
AD1CON1 |= 0x00D4; //PTGO15 primary trigger to start conversion
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Thanks to all who had a look |
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