Power Management
15-46
15.3.9.2
Warm Reset
A warm reset can be generated from either the MPU_RST pin or through
system software. There are several types of warm reset:
-
Global: Resets the DSP, the MPU, and all internal modules through the
SW_RST field, the ARM_RST field, or the DSP_EN field of the MPU reset
control 1 register (ARM_RSTCT1).
-
DSP: Resets the DSP system, with the exception of the configuration
setting. The reset of the associated internal peripherals (DSP interrupt
handler, timers, UART, GPIO, etc.) is controlled from the peripheral reset
signal issued by the DSP. This is done through the SW_RST field, the
DSP_RST field, or the DSP_EN field of the MPU reset control 1 register
(ARM_RSTCT1).
-
MPU: Resets the MPU subsystem. The signal_reset causes an MPU
reset, as does the ARM_RST field of the MPU reset control 1 register
(ARM_RSTCT1).
-
MCU: Resets the peripheral interrupt priority encoder registers and part
of the MPUI control logic.
15.3.9.3
Watchdog Reset (DSP and MPU)
-
MPU watchdog: A system reset (global reset) is generated when the
down-counter underflows (assuming the MPU watchdog timer is
configured as a watchdog timer).
-
DSP watchdog: A DSP reset (reset the DSP and the DSP MMU) is gener-
ated when the down-counter underflows (assuming the DSP watchdog
timer is configured as a watchdog timer)
15.3.9.4
Warm Reset via MPU_RST
As mentioned earlier, one type of warm reset (also called warm boot) is caused
by the MPU_RST input pin being driven active low. In a portable application
initiating a warm-boot via MPU_RST is a very convenient feature since the
removal of battery sourced power is sometimes difficult or impossible within
the application. Such a warm reset is also useful in line–powered systems
when a system restart is desired without cycling power.
The MPU_RST input pin has the following characteristics:
-
When driven active low, this pin activates a warm reset, forcing the MPU
processor to reboot.