Hi Zhengsu,
If you use an 8MHz crystal and run all the time, LPM0 will suit your
needs. LPM3 won't save you anything significant if you are keeping the
high consumption peripherals running.
An interrupt will wake the processor from LPM0 or LPM3 state for he
duration of the interrupt. What happens at the end of the interrupt is
determined by what is popped from the stack. The _BIC_SR_IRQ(LPM3_bits);
macro modifies the stack, so when the status register is popped it will
leave the MPU out of LPM3 mode. _BIC_SR_IRQ(LPM0_bits); behaves
similarly for LPM0.
Why use an 8MHz crystal? It effectively prevents really low power operation.
Regards,
Steve
Zhengsu Gao wrote:
Thank you first.
I use external 8 MHz crystal in LXT1. I want keep the smclk active so
that the ADC, timerB can work in the low power mode, Does the LPM3 can
meet these requirements? I think in LPM3, the SMCLK is disabled, right?
Also, I have a question about coming back out of LPM3 mode(
_BIC_SR_IRQ(LPM3_bits);. If an interrupt is generated, can it
automaticly comes back out of LPM3 mode , or if I need to write code
_BIC_SR_IRQ(LPM3_bits) to pull the MCU out of LPM?
Thanks
Gao
----- Original Message ----- From: <[email protected]>
To: <[email protected]>
Sent: Tuesday, January 18, 2005 6:26 PM
Subject: Re: [Mspgcc-users] about low power mode
Hi,
I am new in mspgcc, can someone please tell me how can I put
microcontroller
into LPM1 mode. Does following code works?
LPM1 does not make much sense. In most cases you do need LPM3.
In the code examples from TI i only found LPM3 and in the
examples from mspgcc LPM3 and LPM4.
I think i've seen some code with LPM1 and LPM2 on a conferece from TI.
LPM1 and LPM2 should work if you replace the string "LPM3" by
"LPM1" or rather "LPM2" in the examples.
Regards,
Rolf
