Tool/software: Code Composer Studio
Our device uses the MSP430F6747A. The problem is that we want to get the power consumption down to about 14µA in LPM4
active mode (before the reset):
- SPI, I2C and 3 UARTs are active (SMCKL)
- Timer A1,A2 and B0 are active (ACKL)
- RTC is on (XT1)
- Interrupts are listening on Port 1
- PMM_CORE_LEVEL_3, SMCKL=25MHz
inactive mode:
- UARTs are initialised, used and then deactivated (SMCKL)
- RTC is ON (XT1)
- Interrupts are listening on Port 1
- PMM_CORE_LEVEL_3, SMCKL=25MHz
- Timer B0 is actived when there is an interrupt on Port 1 (ACKL)
- set LPM4 (__bits_SR_register(LPM4_bits + GIE))
current consumption during the changeover from active to inactive:
- voltage drops, then returns current: 13uA
- start via the debugger: 13uA (after removing the JTAG-Cable)
- start via the watdchdog reset (watchdog used for the SW-Reset):32uA
The problem is that the device could sit in this state for quite a while and drain the battery before reaching the actual duty cycle.