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RENESAS TOOL NEWS on July 1, 2005: RSO-M3T-NC30WA-050701D
A Note on Using the C-Compiler Package
M3T-NC30WA V.5.30 Release 02 |
Please take note of the following problem in using the C-compiler package M3T-NC30WA V.5.30 Release 02 (this compiler package is used for the M16C/60, M16C/30, M16C/20, M16C/10, M16C/Tiny, and R8C/Tiny series of MCUs):
- On assigning a near-qualified variable of 64-bit data type to a far-qualified variable of the same type
- Description
If a near-qualified variable of 64-bit data type* is assigned to a far-qualified variable of the same type, the values in the lower 3rd and 4th bytes of an 8-byte data piece cannot be done.
* Omission of the qualifier is interpreted as qualified to be near.
Example:
--------------------------------------------------------------------
far long long l2;
long long l1;
void func(void)
{
l2 = l1;
}
--------------------------------------------------------------------
- Workaround
When assigning a near-qualified variable of 64-bit data type to a far-qualified variable of the same type, transfer the former variable 2 bytes at a time using asm functions as follows:
- If the variables to reference are auto variables or arguments, use format "$$," and if they are external variables, use format "$$" or "$@."
--------------------------------------------------------------------
far long long l2;
void func(long long l1)
{
asm(" ste.w $$[FB],$@",l1,l2);
asm(" ste.w $$+2[FB],$@+2",l1,l2);
asm(" ste.w $$+4[FB],$@+4",l1,l2);
asm(" ste.w $$+6[FB],$@+6",l1,l2);
}
--------------------------------------------------------------------
- Schedule of Fixing the Problem
We plan to fix this problem in the next release of the product.
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