Part Number: MSP430FR2355
Tool/software: Code Composer Studio
Hello experts,
My customer plan to use MSP430FR2355 and use LPM3 for reducing current consumption.
I got some questions as below. Could you give us support?
1) Low power consumption control
Is there any way to wake up with the receive interrupt of UART in consideration of the low power consumption mode?
<Current use case>
The VLO clock is used as the ACLK count source.
By using the timer's wake-up interrupt, we release LPM3 mode (approx. 1μA)
2) Stable waiting time of the clock
Could you tell me how long does it take to stabilize the clock control register when it is stopped and started?
The time which it take to completely stop after “CSCTL8” register bit clear
The time which it take to start and stabilize the clock after ”CSCTL8” register bit set
<Current use case>
Clock stop and start-up are used for transition to LPM3
MCLK : REFO+DCO 2MHz
SMCLK : UART 9600bps
ACLK : Used in the sleep mode
Currently, the following procedure is used for sleep and wake-up control. Do you have a problem with the procedure?
// Sleep operation
CSCTL8 = MODOSCREQEN_0 | MCLKREQEN_0 | SMCLKREQEN_0 | ACLKREQEN_1; // [clock setting] ACLK only operate (in power saving mode)
_no_operation();
_bis_SR_register(LPM3_bits | GIE); // Transition to low power mode<LPM3>
_no_operation();
// Wake-up operation
CSCTL8 = MODOSCREQEN_0 | MCLKREQEN_1 | SMCLKREQEN_1 | ACLKREQEN_0; // [clock setting] ACLK only stop (normal mode)
_no_operation();
_bic_SR_register_on_exit(LPM3_bits); // Canceling low power mode
_no_operation();
3) FRAM control
Is it correct to assume that the specifications listed on datasheet P56 are common to both the data FRAM and the program FRAM?
Also, what is the current consumption (one word access) when using MCLKs at 2MHz?
4) AD conversion control
Is there any way to effectively control by switching between two channels?
Currently, we switch the channels with single channel mode. Are there any point which we should take care (wait time, turning off ADCON, etc.)?
I would appreciate if you would give me reply.
Thanks and best regards,
Ryo Akashi
