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Trying to Get Our PWM Interrupts to Fire
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Previous: 'Studying Calling Conventions'
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0:08Recap and set the stage for the day with a working toolchain
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0:08Recap and set the stage for the day with a working toolchain
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0:08Recap and set the stage for the day with a working toolchain
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2:26Make and upload pwm_speed_test to the HiFive1
2:26Make and upload pwm_speed_test to the HiFive1
2:26Make and upload pwm_speed_test to the HiFive1
4:08Connect to and reset the HiFive1, and see "Hello, World!"
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4:08Connect to and reset the HiFive1, and see "Hello, World!"
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4:08Connect to and reset the HiFive1, and see "Hello, World!"
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6:22Check the Freedom E SDK's current init.c file1 and the forums2 for information on busy-looping to let the uart settle
6:22Check the Freedom E SDK's current init.c file1 and the forums2 for information on busy-looping to let the uart settle
6:22Check the Freedom E SDK's current init.c file1 and the forums2 for information on busy-looping to let the uart settle
10:04Thoughts on dynamically setting how long to wait, based on the CPU frequency
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10:04Thoughts on dynamically setting how long to wait, based on the CPU frequency
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10:04Thoughts on dynamically setting how long to wait, based on the CPU frequency
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11:41Build, upload but unfortunately fail to connect to the HiFive1
11:41Build, upload but unfortunately fail to connect to the HiFive1
11:41Build, upload but unfortunately fail to connect to the HiFive1
13:42Try to debug our program with gdb3
13:42Try to debug our program with gdb3
13:42Try to debug our program with gdb3
16:16Try to print "Hello World!" in the infinite loop
16:16Try to print "Hello World!" in the infinite loop
16:16Try to print "Hello World!" in the infinite loop
17:07Connect to the HiFive1 and see garbage being printed
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17:07Connect to the HiFive1 and see garbage being printed
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17:07Connect to the HiFive1 and see garbage being printed
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17:50Add "\r" to the end of the printf
17:50Add "\r" to the end of the printf
17:50Add "\r" to the end of the printf
18:14Connect and see it printing "Hello, World!"
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18:14Connect and see it printing "Hello, World!"
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18:14Connect and see it printing "Hello, World!"
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18:44Revert to performing the "wfi" in the loop, and printing "Hello World!" before it, build and upload it
18:44Revert to performing the "wfi" in the loop, and printing "Hello World!" before it, build and upload it
18:44Revert to performing the "wfi" in the loop, and printing "Hello World!" before it, build and upload it
19:15Reset the HiFive1 and see no output
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19:15Reset the HiFive1 and see no output
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19:15Reset the HiFive1 and see no output
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20:19Comment out the "wfi" and ensure that the while scope loops infinitely
20:19Comment out the "wfi" and ensure that the while scope loops infinitely
20:19Comment out the "wfi" and ensure that the while scope loops infinitely
21:57Connect to the HiFive1 and see our "Hello, World!"
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21:57Connect to the HiFive1 and see our "Hello, World!"
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21:57Connect to the HiFive1 and see our "Hello, World!"
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22:27Decide against using the "wfi" instruction
22:27Decide against using the "wfi" instruction
22:27Decide against using the "wfi" instruction
23:23Connect to the HiFive1, see the power lights flickering, and reconnect the power cable
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23:23Connect to the HiFive1, see the power lights flickering, and reconnect the power cable
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23:23Connect to the HiFive1, see the power lights flickering, and reconnect the power cable
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24:53Try to upload and connect, but still see no output
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24:53Try to upload and connect, but still see no output
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24:53Try to upload and connect, but still see no output
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25:40Try a full rebuild and upload
25:40Try a full rebuild and upload
25:40Try a full rebuild and upload
26:02Connect to the HiFive1 and see a "Hello, World!" but no pwm interrupt
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26:02Connect to the HiFive1 and see a "Hello, World!" but no pwm interrupt
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26:02Connect to the HiFive1 and see a "Hello, World!" but no pwm interrupt
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27:02Closely read through the code, and compare it with the led_fade.c demo
27:02Closely read through the code, and compare it with the led_fade.c demo
27:02Closely read through the code, and compare it with the led_fade.c demo
30:03Configure the PWM in ENALWAYS mode and with PWM_CMP0 = 04
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30:03Configure the PWM in ENALWAYS mode and with PWM_CMP0 = 04
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30:03Configure the PWM in ENALWAYS mode and with PWM_CMP0 = 04
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36:48Connect to the HiFive1, see the "Hello, World!" but still no interrupts
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36:48Connect to the HiFive1, see the "Hello, World!" but still no interrupts
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36:48Connect to the HiFive1, see the "Hello, World!" but still no interrupts
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37:29#include platform.h and set the pwmscp0ip bit5
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37:29#include platform.h and set the pwmscp0ip bit5
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37:29#include platform.h and set the pwmscp0ip bit5
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📖
41:54Connect to the HiFive1 and see no change
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41:54Connect to the HiFive1 and see no change
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41:54Connect to the HiFive1 and see no change
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42:44Scour the Freedom E SDK demos for interrupts that use the PWM
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42:44Scour the Freedom E SDK demos for interrupts that use the PWM
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42:44Scour the Freedom E SDK demos for interrupts that use the PWM
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44:27See how the global_interrupts demo handles the interrupts
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44:27See how the global_interrupts demo handles the interrupts
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44:27See how the global_interrupts demo handles the interrupts
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49:45Determine that the only difference between global_interrupts and our pwm_speed_test is that we are not setting the priority or the compare registers
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49:45Determine that the only difference between global_interrupts and our pwm_speed_test is that we are not setting the priority or the compare registers
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49:45Determine that the only difference between global_interrupts and our pwm_speed_test is that we are not setting the priority or the compare registers
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50:45Try to use exactly the same PWM configuration as global_interrupts
50:45Try to use exactly the same PWM configuration as global_interrupts
50:45Try to use exactly the same PWM configuration as global_interrupts
53:08Connect to and reset our HiFive1, but still see no PWM interrupt
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53:08Connect to and reset our HiFive1, but still see no PWM interrupt
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53:08Connect to and reset our HiFive1, but still see no PWM interrupt
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54:24Try to set the priority and enable timer interrupts
54:24Try to set the priority and enable timer interrupts
54:24Try to set the priority and enable timer interrupts
56:57Reset our HiFive1 and see a "trap"
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56:57Reset our HiFive1 and see a "trap"
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56:57Reset our HiFive1 and see a "trap"
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58:29Note that global_interrupts is setting a handler for the timer interrupt and calling set_timer()
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58:29Note that global_interrupts is setting a handler for the timer interrupt and calling set_timer()
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58:29Note that global_interrupts is setting a handler for the timer interrupt and calling set_timer()
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59:20Introduce handle_m_time_interrupt()
59:20Introduce handle_m_time_interrupt()
59:20Introduce handle_m_time_interrupt()
1:04:41Connect to our HiFive1 and see one instance of "handling timer interrupt" before a "trap", yet no "Hello, World!"
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1:04:41Connect to our HiFive1 and see one instance of "handling timer interrupt" before a "trap", yet no "Hello, World!"
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1:04:41Connect to our HiFive1 and see one instance of "handling timer interrupt" before a "trap", yet no "Hello, World!"
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1:06:29Search the demos for MTIP and consult demo_gpio for their timer handling
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1:06:29Search the demos for MTIP and consult demo_gpio for their timer handling
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1:06:29Search the demos for MTIP and consult demo_gpio for their timer handling
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1:07:27Make handle_m_time_interrupt() disable and reenable the MTIP
1:07:27Make handle_m_time_interrupt() disable and reenable the MTIP
1:07:27Make handle_m_time_interrupt() disable and reenable the MTIP
1:10:05Connect to our HiFive1 and see the same output
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1:10:05Connect to our HiFive1 and see the same output
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1:10:05Connect to our HiFive1 and see the same output
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1:10:29Make handle_m_time_interrupt() print "leaving timer interrupt"
1:10:29Make handle_m_time_interrupt() print "leaving timer interrupt"
1:10:29Make handle_m_time_interrupt() print "leaving timer interrupt"
1:11:03Connect to our HiFive1 and see the "leaving timer interrupt"
1:11:03Connect to our HiFive1 and see the "leaving timer interrupt"
1:11:03Connect to our HiFive1 and see the "leaving timer interrupt"
1:11:34Comment out the set_csr(mie, MIP_MTIP) call in main()
1:11:34Comment out the set_csr(mie, MIP_MTIP) call in main()
1:11:34Comment out the set_csr(mie, MIP_MTIP) call in main()
1:11:53Connect to our HiFive1 and see that we are still trapping
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1:11:53Connect to our HiFive1 and see that we are still trapping
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1:11:53Connect to our HiFive1 and see that we are still trapping
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1:12:09Comment out the following set_csr() calls
1:12:09Comment out the following set_csr() calls
1:12:09Comment out the following set_csr() calls
1:12:40Connect to our HiFive1 and see the "Hello, World!"
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1:12:40Connect to our HiFive1 and see the "Hello, World!"
🏃
1:12:40Connect to our HiFive1 and see the "Hello, World!"
🏃
1:13:13Uncomment the set_csr(mstatus, MSTATUS_MIE) call in main()
1:13:13Uncomment the set_csr(mstatus, MSTATUS_MIE) call in main()
1:13:13Uncomment the set_csr(mstatus, MSTATUS_MIE) call in main()
1:13:35Connect to our HiFive1 and hit the trap
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1:13:35Connect to our HiFive1 and hit the trap
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1:13:35Connect to our HiFive1 and hit the trap
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1:14:14Try various combinations of interrupts, run the program and always hit the trap
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🖮
1:14:14Try various combinations of interrupts, run the program and always hit the trap
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1:14:14Try various combinations of interrupts, run the program and always hit the trap
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🖮
1:16:27Comment out everything except the set_csr() and printf() calls
1:16:27Comment out everything except the set_csr() and printf() calls
1:16:27Comment out everything except the set_csr() and printf() calls
1:17:10Connect to our HiFive1 and still trap
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1:17:10Connect to our HiFive1 and still trap
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1:17:10Connect to our HiFive1 and still trap
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1:17:54Make and upload demo_gpio
1:17:54Make and upload demo_gpio
1:17:54Make and upload demo_gpio
1:18:49Reset our HiFive1 and see everything working as expected
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1:18:49Reset our HiFive1 and see everything working as expected
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1:18:49Reset our HiFive1 and see everything working as expected
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1:19:12Read the documentation for some gotcha related to mstatus6
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1:19:12Read the documentation for some gotcha related to mstatus6
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1:19:12Read the documentation for some gotcha related to mstatus6
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1:21:13Wrap it up with the determination to continue our investigation next time
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1:21:13Wrap it up with the determination to continue our investigation next time
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1:21:13Wrap it up with the determination to continue our investigation next time
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Next: 'Getting the PWM Interrupts to Fire'
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