Getting captures to work

At the moment, with my custom code to capture the IPWM, everthing is working other than the capture setup.

I have ISR routines that are getting called on a falling edge, but depending on the setup, I can only get IPWM1 working.

Here is my attempt to sort it out with the code. I have been using the capture simulink block to create the capture unit setup.

/**************************************
* CUSTOM CAPTURE UNITS INITIALISATION *
**************************************/

// Capture unit setup: EMG p 3-3, 3-5 and B-3
// EvaRegs.CAPCONA.all = 13992; // (0011 0110 1010 1000) all 3 with timer 1 - NOT WORKING
// EvaRegs.CAPCONA.all = 9384; // (0010 0100 1010 1000) only 1 and 2 with timer 1 and 2 - NOT WORKING
// EvaRegs.CAPCONA.all = 8916; // (0010 0010 1101 0100) only 1 - 1 WORKING
// EvaRegs.CAPCONA.all = 9896; // (0010 0110 1010 1000) only 2 - NOT WORKING
// EvaRegs.CAPCONA.all = 5800; // (0001 0110 1010 1000) only 3 - NOT WORKING

// B15 - CAPRES : ALWAYS 0
// B14 - CAP12EN : 1 FOR CAP2 ENABLED?
// B13 - CAP12EN : 1 FOR CAP1 ENABLED?
// B12 - CAP3EN : 1 FOR CAP3 ENABLED

// B11 - RESERVED
// B10 - CAP3TSEL : 1 FOR TIMER1?
// B9 - CAP12TSEL : 1 FOR TIMER1 FOR BOTH?
// B8 - CAP3TOADC : ALWAYS 0

// B7 - CAP1EDGE : 1 FOR FALLING?
// B6 - CAP1EDGE : 0 FOR NOT RISING?
// B5 - CAP2EDGE : 1 FOR FALLING?
// B4 - CAP2EDGE : 0 FOR NOT RISING?

// B3 - CAP3EDGE : 1 FOR FALLING?
// B2 - CAP3EDGE : 0 FOR NOT RISING?
// B1 - RESERVED
// B0 - RESERVED

// I think that the actual should be: (0111 0110 1010 1000) - 30376 or 0x76A8
EvaRegs.CAPCONA.all = 0x76A8;



after a lot of stuffing around I looked in the index an found on 5-19 that there is the explanation that I had been after. From that I think that simulink got it correct and it should be:

0 - clear all registers of capture units to 0
01 - enable captures 1 and 2
1 - enable capture 3

0 - reserved
1 - select timer 1 for cap3
1 - select timer 1 for cap1 and 2
0 - no action

10 - cap1 falling edge
10 - cap2 falling edge

10 - cap2 falling edge
00 - reserved


just noticed something interesting in that the only one that i have working is actually using the rising edge. I will try:

0 - clear all registers of capture units to 0
01 - enable captures 1 and 2
1 - enable capture 3

0 - reserved
1 - select timer 1 for cap3
1 - select timer 1 for cap1 and 2
0 - no action

01 - cap1 rising edge
01 - cap2 rising edge

01 - cap2 rising edge
00 - reserved

0011 0110 0101 0100

= decimal 13908

= 0x3654

using the rising edge, I only get in Time1s in and no Time2s. I will recheck what happens if I use the falling edge.


// 1,2,3 enabled, falling, all on timer 1: 0011 0110 1010 1000 = decimal 13992 = 0x36A8
EvaRegs.CAPCONA.all = 0x36A8;

I still only get Time1s. I will have to go back to the setup that only has CAP1 and see why it is working.


// 1, enabled, falling, timer 1: 0010 0110 0101 0100 = = 0x2654
EvaRegs.CAPCONA.all = 0x2654;

as expected, there is now nothing for CAP3, however for cap1 and cap2 there is still only time1 available. HOW IS THIS DIFFERENT FROM THE OTHER EXPERIMENT THAT IS WORKING?

// EvaRegs.CAPCONA.all = 8916; // (0010 0010 1101 0100) only 1 - 1 WORKING

BLOODY HELL - I AM IN IDIOT.... TRY DETECTING BOTH EDGES!!!!!!


// 1, enabled, rising and falling, timer 1: 0011 0110 1111 1100 = = 0x36FC
EvaRegs.CAPCONA.all = 0x36FC;

GETTING THERE!

all signals now have a Time1 and Time2, however only IPWM1 is nice and constant. I have to understand why the others are not being good!.


maybe I have connected XINT2 and XINT13 around the wrong way. Simplest way to check that is in software.

that did not seem to help. - change back and check the pulses in hardware.

Just noticed that I am acknowlging int1 in the Xint13 isr. Better fix that.


// Acknowledge interrupt to receive more interrupts from PIE group 1
// PieCtrlRegs.PIEACK.all = PIEACK_GROUP1;

may have made a bit of a difference but not solved the problem.

I will check that it is not the code by copying that from the ISR for XINT1 to the others.

checked that - not fixed

also tried using CAP1 in all three ISRs but that stuffed things up further.

I have checked on the hardware that the same signals is getting to XINT2/CAP2 and XINT13/CAP3

It is also worth noting that all the signals look the same so I should be getting a very similar pulse width.

must be home time now. I hope I have some brillinat ideas to solve this tomorrow.