Differences

This shows you the differences between two versions of the page.

--- microcontrollers:msp430fr5969_low_power_modes_and_interrupts [2024/10/30 19:27] – created ibchadmin
+++ microcontrollers:msp430fr5969_low_power_modes_and_interrupts [2024/10/30 19:44] (current) – [Low Power Modes] ibchadmin
@@ Line 1: / Line 1: @@
 ====== MSP430FR5969 Low Power Modes and Interrupts ======
+===== Low Power Modes =====
+{{ :microcontrollers:lpm1.png?direct&600 |}}
+Low power modes can drastically reduce power consumption, going from around a hundred microamps in active mode to under a microamp (or tenths of a microamp) in the 3.x and 4.x low power modes.
+==== LPMs in C ====
+  * Use the following command to enter the x mode, where x = 0,1,2,3,4,3.5,or 4.5:
+_bis_SR_register( GIE | LPMx_bits );
+bis =  bit set
+  * To exit LPMx  use the following command inside the Interrupt Service Routine ISR, where x = 0,1,2,3,4,3.5,or 4.5 :
+__bic_SR_register_on_exit(LPMx_bits );
+ bic = bit clear
+==== Low Power Implementation Notes ====
+  * Choose the appropriate LPM that suits your application. For example, if you use the SPI communication, you need a clock. As result, you have to choose the LPM where the clock source for your SPI is enabled.
+  * To support low power design, configure all unused pins as an input with pull down resistor to prevent them from floating.
+===== Interrupts =====
+==== Interrupt Priority ====
+{{ :microcontrollers:interrupt1.png?direct&600 |}}
+==== Interrupt Implementation Notes ====
+  * Be aware of the interrupts priorities for the MCU that you are working on.
+  * There are specific interruptible ports. Not all ports of the chip are interruptible.
+**For port interrupts:**
+  * If the interrupt will fire when the port status changed from Low to High, you should configure the port to be pulled down.
+  * If the interrupt will fire when the port status changed from high to low, you should configure the port to be pulled up.
+===== References =====
+  * Interrupt : https://training.ti.com/msp430-workshop-series-5-12-interrupts?cu=1135311
+  * Low-Power Optimization :  https://training.ti.com/msp430-workshop-series-7-12-low-power-optimization?cu=1135311