MSP430F6720: possible to use 64 bit time_t as in MSP432 series MCU?

Zhiyong Li (FT)

Part Number: MSP430F6720
Other Parts Discussed in Thread: MSP430F6736

Hi,

I am trying to proof a product for Y2038 problem, found out that TI compiler as of v20.2.4 still uses 32bit/4byte time_t

The following is test code for mktime():

struct tm calendarTime;
calendarTime.tm_year = RTCYEAR - 1970;
calendarTime.tm_mon = RTCMON - 1;
calendarTime.tm_mday = RTCDAY;
calendarTime.tm_hour = RTCHOUR;
calendarTime.tm_min = RTCMIN;
calendarTime.tm_sec = RTCSEC;
time_t seconds = mktime(&calendarTime);
uint8_t debugInfo[48];
sprintf(debugInfo, "time_t size = %d, seconds = %010lu", sizeof(time_t), seconds);
printDebugInfo(debugInfo, 38);  // output to console via UART

I get the following output in console:

2021-04-19 18:52:55, time_t size = 4, seconds = 1618771975 // Unix epoch time since 1970-01-01 00:00:00

As mentioned in another post, time_t can be changed to 64bit for MSP432 series MCU. Can we do this for MSP430 as well?

Thanks.

over 3 years ago

0 Eason Zhou over 2 years ago

TI__Mastermind 32900 points

I think you can refer to this one:

Creating a 32-Bit Timer From a 16-Bit Timer Chain

+1 Chester Gillon over 2 years ago

Guru 92251 points

Zhiyong Li (FT) said:
I am trying to proof a product for Y2038 problem, found out that TI compiler as of v20.2.4 still uses 32bit/4byte time_t

TI MSP430 v20.2.4 compiler can be changed to use 64-bit/8 byte time_t by adding the pre-defined symbol __TI_TIME_USES_64

Not that as per CCS/CC1312R: Have Processors Wiki pages relating to clock and time Functions and CIO been migrated to other pages? the description of __TI_TIME_USES_64 is currently missing from the documentation.

The attached project for a MSP430F6736 using MSP430 v20.2.4 compiler has two build configurations:

1. Debug_32bit_time_t which doesn't define __TI_TIME_USES_64 and gets a 4 byte time_t:

time_t size = 4, seconds = 2673414003

2. Debug_64bit_time_t which does define __TI_TIME_USES_64:

and gets a 8 byte time_t:

time_t size = 8, seconds = 64888956243

Note that in the attached example I didn't configure the RTC so the actual seconds value are not meaningful, but the report of the sizeof(time_t) shows the effect.

MSP430F6736_time_t_size.zip

0 Zhiyong Li (FT) over 2 years ago in reply to Chester Gillon

Expert 2450 points

Hi Mr. Gillon,

Thanks for solving my problem again.

Btw, is this screenshot from MacOS or Linux version of CCS? If so what is your experience of using MacOS/Linux version? I am considering changing OS for development. Other tools I tried seem to run a lot faster on Mac/Ubuntu than Windows.

+1 Chester Gillon over 2 years ago in reply to Zhiyong Li (FT)

Guru 92251 points

Zhiyong Li (FT) said:
Btw, is this screenshot from MacOS or Linux version of CCS?

The screenshot was from the Linux version of CCS.

Zhiyong Li (FT) said:
If so what is your experience of using MacOS/Linux version?

I use a PC which is able to dual boot to Windows 10 or Ubuntu 18.04, the reason being some that some tools only work on one OS.

I haven't done any comparative measurements of the same tools under Windows and Linux, but Windows seems to more running background processes which seem to slow things down generally.

0 Zhiyong Li (FT) over 2 years ago in reply to Chester Gillon

Expert 2450 points

Thanks for the information. The difference of ARMC6 compilation time for Mbed projects is mind-boggling. The same PC running Ubuntu 20.04 finishes compilation in 40 seconds while Windows 10 needs 2 minutes 50 seconds.

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MSP430F6720: possible to use 64 bit time_t as in MSP432 series MCU?