 |
|
|
RENESAS TOOL NEWS on May 16, 2005: RSO-M3T-NC30WA_1-050516D
A Note on Using
the M3T-NC30WA C-Compiler Package
--On Using the #pragma ADDRESS Directive-- |
Please take note of the following problem in using the M3T-NC30WA C-compiler package:
- On using the #pragma ADDRESS directive
- Versions Concerned
M3T-NC30WA V.1.00 Release 1 through V.5.30 Release 02
(This C compiler package is used for the M16C/60, M16C/30, M16C/20, M16C/10,
M16C/Tiny, and R8C/Tiny series of MCUs.)
- Description
Bit-accessing a variable defined by using the #pragma ADDRESS directive may result in an assemble error.
- 2.1 Conditions
- This problem occurs if the following conditions are all satisfied:
| (1) |
There exists a variable defined by using the #pragma ADDRESS directive, and the variable is a union of the array type. |
| (2) |
The value of the address specified by the #pragma ADDRESS directive in (1) is less than 01FFFH. |
| (3) |
The value of the address of the bit-accessed variable is greater than 01FFFH. |
- 2.2 Example
-
--------------------------------------------------------------------
typdef struct{
unsigned char b0:1;
unsigned char b1:1;
unsigned char b2:6;
}BIT;
#pragma ADDRESS bit 01FFEH
BIT bit[10];
void func(void)
{
bit[2].b0 = 1;
}
--------------------------------------------------------------------
- Workaround
Bit-access the variable using an asm function.
--------------------------------------------------------------------
typdef struct{
unsigned char b0:1;
unsigned char b1:1;
unsigned char b2:6;
}BIT;
#pragma ADDRESS bit 01FFEH
BIT bit[10];
void func(void)
{
asm(" or.b #01H,$$",bit[2].b0);
}
--------------------------------------------------------------------
- Schedule of Fixing the Problem
We plan to fix this problem in the next release of the product.
|
|
