Watchdog Timer
Watchdog Timer
Watchdog Timer
Watchdog Timer
Resets the C28x if the CPU crashes
Resets the C28x if the CPU crashes
Watchdog counter runs independent of CPU
Watchdog counter runs independent of CPU
If counter overflows, reset or interrupt is
If counter overflows, reset or interrupt is
triggered
triggered
CPU must write correct data key sequence to
CPU must write correct data key sequence to
reset the counter before overflow
reset the counter before overflow
Watchdog must be serviced (or disabled)
Watchdog must be serviced (or disabled)
within ~4.37
within ~4.37
m
m
s after reset (30 MHz
s after reset (30 MHz
OSCCLK for 150 MHz device)
OSCCLK for 150 MHz device)
This translates into 131,072 instructions!
This translates into 131,072 instructions!
The watchdog timer provides a safeguard against CPU crashes by automatically initiating a reset
if it is not serviced by the CPU at regular intervals. In motor control applications, this helps
protect the motor and drive electronics when control is lost due to a CPU lockup. Any CPU reset
will revert the PWM outputs to a high-impedance state, which should turn off the power
converters in a properly designed system.
The watchdog timer is running immediately after system power-up/reset, and must be dealt with
by software soon after. Specifically, you have 4.37 ms (for a 150 MHz device) after any reset
before a watchdog initiated reset will occur. This translates into 131,072 instruction cycles,
which is a seemingly tremendous amount! Indeed, this is plenty of time to get the watchdog
configured as desired and serviced. A failure of your software to properly handle the watchdog
after reset could cause an endless cycle of watchdog initiated resets to occur.
C28x - System Initialization
5 - 5
Содержание C28 Series
Страница 64: ...Summary 3 16 C28x Peripheral Registers Header Files ...
Страница 78: ...Interrupt Sources 4 14 C28x Reset and Interrupts ...
Страница 218: ...Lab 9 DSP BIOS 9 22 C28x Using DSP BIOS ...
Страница 244: ...Lab 10 Programming the Flash 10 26 C28x System Design ...
Страница 273: ...Appendix A eZdsp F2812 C28x Appendix A eZdsp F2812 A 1 ...
Страница 275: ...Appendix eZdsp F2812 eZdsp F2812 Connector Header and Pin Diagram C28x Appendix A eZdsp F2812 A 3 ...
Страница 276: ...Appendix P2 Expansion Interface A 4 C28x Appendix A eZdsp F2812 ...
Страница 277: ...Appendix P4 P8 P7 I O Interface C28x Appendix A eZdsp F2812 A 5 ...
Страница 278: ...Appendix A 6 C28x Appendix A eZdsp F2812 ...
Страница 279: ...Appendix P5 P9 Analog Interface C28x Appendix A eZdsp F2812 A 7 ...
Страница 281: ...Appendix JP7 JP8 JP11 JP12 Boot Mode Select JP9 PLL Disable DS1 DS2 LEDs C28x Appendix A eZdsp F2812 A 9 ...
Страница 282: ...Appendix A 10 C28x Appendix A eZdsp F2812 TP1 TP2 Test Points ...