SPRUIZ1B July 2023 – August 2024 TMS320F28P650DH , TMS320F28P650DK , TMS320F28P650SH , TMS320F28P650SK , TMS320F28P659DH-Q1 , TMS320F28P659DK-Q1 , TMS320F28P659SH-Q1
STANDBY is a more aggressive low-power mode that gates both the CPU clock and any peripheral clocks derived from the CPU SYSCLK. The watchdog however, is left active. Like IDLE, this mode affects only one CPU subsystem. The other CPU subsystem and all of the peripherals are unaffected. STANDBY is good for an application where the wake-up signal comes from an external system (or CPU subsystem) rather than a peripheral input.
An NMI (or optionally) a watchdog interrupt or a configured GPIO can wake the CPU from STANDBY mode. Each GPIO from GPIO0-63 can be configured to wake the CPU when the GPIO are driven active low. Upon wakeup, the CPU receives the WAKEINT interrupt if configured.
IPC interrupt 1 (flag 0), an NMI fired to the other CPU, or (optionally) a watchdog interrupt, wakes the CPU subsystem up from STANDBY mode. Any of GPIO0-63 can also be configured to wake up the subsystem when the GPIO is driven active low. Upon wakeup, the CPU receives a WAKEINT interrupt, even if the CPU was woken by an IPCINT1 signal.
To enter STANDBY mode:
To wake up from Standby mode:
At the end of the qualification period, the PLL enables the CLKIN to the CPU and the WAKEINT interrupt is latched in the PIE block. The WAKEINT interrupt can also triggered by IPCINT1 sent from the other CPU and a watchdog interrupt.
The CPU is now out of STANDBY mode and can resume normal execution.
If CPU2 is in STANDBY mode, writing a 1 to the RESET bit of the CPU2RESCTL register has no effect. CPU2 can be reset by any chip-level reset (POR, XRSn, CPU1.WDRSn, or CPU1.NMIWDRSn). Alternately, CPU2 can be woken up by any configured wake-up event.
If CPU2 is in STANDBY mode and the debugger is connected, executing a debug reset on CPU2 has no effect. To wake the CPU2 with the debugger, Click Run, Single Step, or Step over in the Debug toolbar. The CCS IDE prompts the user requesting to bring the CPU out of the low-power mode. Click Yes. This wakes CPU2 from STANDBY and continues execution.