CCS :: View topic - Bit shifting

CCS C Software and Maintenance Offers

FAQ

Official CCS Support

Profile Log in to check your private messages Log in

CCS does not monitor this forum on a regular basis.

Please do not post bug reports on this forum. Send them to CCS Technical Support

Bit shifting

CCS Forum Index -> General CCS C Discussion

View previous topic :: View next topic

Author

Message

Prefekt

Joined: 21 Oct 2010
Posts: 85

Bit shifting

Posted: Fri Oct 05, 2012 2:41 pm

Reply with quote

Hello,

I'm confused...

I have a char array

Code:

a[0] = '0';
a[1] = '1';

now I would like to set the output with the a[1] value...

for example:

Code:

a[1] = 3;
out = 00000100;

or

Code:

a[1] = 7;
out = 01000000;

I try:

Code:

out =1;
out = out << a[1];
output_d(out);

not working..

anybody an idea?

thanks

PCM programmer

Joined: 06 Sep 2003
Posts: 21708

Posted: Fri Oct 05, 2012 4:54 pm

Reply with quote

You want to convert a bit number to a bitmask. Use a lookup table.
With the following table placed above main(), you can now put in code
in main() to get the bitmask. Use a number from 0 to 7 as the index
to get the bitmask for bit number 0 to 7. For bit 0, you will get 0x01,
and for bit 7 you will get 0x80, etc.

Code:

int8 const bitmask_table[] = {0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80};

To use your incoming numbers as index values for this table, you will
need to convert them from ASCII characters to binary digits in the range
from 0 to 7.

This post may have some hints.
http://www.ccsinfo.com/forum/viewtopic.php?t=48590&start=3

Display posts from previous:

	CCS Forum Index -> General CCS C Discussion	All times are GMT - 6 Hours
Page 1 of 1

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

Powered by phpBB © 2001, 2005 phpBB Group