CCS/MSP-TS430DA38: MSP430F2252

siranjeevi mahadevan

Part Number: MSP-TS430DA38
Other Parts Discussed in Thread: MSP430F2252

Tool/software: Code Composer Studio

HI SIR,

i have run UART sample code from ti resource explore .."sizeof string1 - 1" in this line sizeof variable name with - 1 ..actually we are call sizeof funtion just return size of (int (16), char(8), etc..) .but here sizeof varible name subtract 1 ?which one can subtract value or datatype(like int , char, etc..) SAMPLE CODE link from ti resource explore/msp430f2252/software/device/msp430f2252/peripheral example/ register level/UART_007 EXAMPLE ..CAN YOU CHECK SIR..

THANKING YOU

SIRU

over 5 years ago

0 George Mock over 5 years ago

TI__Guru**** 232960 points

That source file includes these lines ...

char string1[8];

/* many lines later, inside a function */

   if (j > sizeof string1 - 1)

Part of the confusion arises from how the last line is written. This is equivalent, but a bit clearer ...

   if (j > sizeof(string1) - 1)

The built-in operator sizeof returns the size, in bytes, of its argument. In this case sizeof(string1) evaluates to the value 8. So, after all the constant expressions are evaluated, this is the same as ...

   if (j > 7)

Thanks and regards,

-George

0 Tomasz Kocon over 5 years ago in reply to George Mock

Guru 26200 points

George,
It took me 2-3 minutes to find an answer and I gave up.
Your job is really impressing!

0 siranjeevi mahadevan over 5 years ago in reply to George Mock

Intellectual 330 points

thank you so much for given result.

and small dought j value can not get here i think string[8] = string[j] so j=8 it s right sir?

then start condition apply like if(j > sizeof string1 -1)

thank you sir,

siranjeevi.m

0 Tomasz Kocon over 5 years ago in reply to siranjeevi mahadevan

Guru 26200 points

siranjeevi mahadevan said:
i think string[8] = string[j] so j=8 it s right sir?

No, it is not right.
If your string is "AAAAAAAA" then
string[7] == string[j] for 0 <= j < 8

Moreover, your string declaration
char string1[8];
means that both i and j indexes cannot axceed 7 to access string1 data.

siranjeevi mahadevan said:
then start condition apply like if(j > sizeof string1 -1)

if(j > sizeof string1 -1) means that a string1 is full of data and that this data should be transmitted

0 siranjeevi mahadevan over 5 years ago in reply to Tomasz Kocon

Intellectual 330 points

thank you sir,

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CCS/MSP-TS430DA38: MSP430F2252