Floating point in Nios SDK

[Maxlim]

Hello...
Can anybody tell me that why Nios SDK cant display floating point
datatype if I include excalibur.h as the header file? The C code that
process simple floating point works correctly only if I exclude the
excalibur.h file. The problem occur when I need the software
subroutine for the standand peripherals but I cant display the
processing time if the calculation formula involved floating point.

 

[Jesse Kempa]

maxlim79@hotmail.com (Maxlim) wrote in message news:<a6140565.0401042045.3d8123f@posting.google.com>...

Hello...
Can anybody tell me that why Nios SDK cant display floating point
datatype if I include excalibur.h as the header file? The C code that
process simple floating point works correctly only if I exclude the
excalibur.h file. The problem occur when I need the software
subroutine for the standand peripherals but I cant display the
processing time if the calculation formula involved floating point.

Hi Maxlim,

The reason for this is the printf() routine compiled into your
library, defined when you include 'excalibur.h' in your C code is a
'small' printf() that does not support floating point numbers to save
on space (useful for systems running out of on-chip memory). This is
an SDK option that can be switched for printf() that supports floating
point.

You can disable this small printf routine and use the full-sized one
(and still use excalibur.h in your source code) by opening SOPC
Builder, editing the Nios CPU settings for your processor, and under
"Software" tab, un-checking the "Use small printf" checkbox. After
this, re-generate the SDK and re-compile your code; you should now be
able to print floating point numbers correctly while including
excalibur.h. I just tried a simple test to verify this, so if you have
any questions please email me and I'll send you the example.

Regards,

Jesse Kempa
Altera Corp.
jkempa at altera dot com