Implicit type convertion

[misra-c]

In section 6.10.4, we indicate that unsigned values between 0 and 255 are treated as having an underlying type of unsigned 8 bits.

Therefore 10U is treated as having an underlying type of unsigned 8 bit .

Your code example

Code:

U16 u16value;
U8 u8value;

u16value = (U16) u8value / 10U;

should not generate any warnings.

Your code example

Code:

U16 u16value;
U8 u8value;

u8value = (U16) u8value / (U16)10U;

should generate a warning because a U16 expression is being narrowed into a U8 result - 10.1a.

Code:

U8 u8a;
U8 u8b;
U8 u8c;

U8a = (U32) u8b / (U32) u8c;

should generate a warning because a U32 expression is being narrowed into a U8 result - 10.1a.

Writing just

Code:

U8a = u8b / u8c;

is compliant. The result of a U8 expression is stored in a U8 variable.

This is an area were MISRA-C:2004 is significantly different than MISRA-C:1998.