1.3.3. Saturation: __sat. Altium TriCore

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typedef volatile union

{

struct

{

unsigned __sfrbit32 SRPN : 8; /* Service Priority Number */

unsigned __sfrbit32 : 2;

unsigned __sfrbit32 TOS : 2; /* Type-of-Service Control */

unsigned __sfrbit32 SRE : 1; /* Service Request Enable Control */

unsigned __sfrbit32 SRR : 1; /* Service Request Flag */

unsigned __sfrbit32 CLRR : 1; /* Request Flag Clear Bit */

unsigned __sfrbit32 SETR : 1; /* Request Flag Set Bit */

unsigned __sfrbit32 : 16;

} B;

int I;

unsigned int U;

} LBCU_SRC_type;

Read-only fields can be marked by using the const

keyword.

The SFR is defined by a cast to a ‘typedef-ed union’ pointer. The SFR address is given in parenthesis.

Read-only SFRs are marked by using the const

keyword in the macro definition.

#define LBCU_SRC (*(LBCU_SRC_type*)(0xF87FFEFCu))

/* LBCU Service Control Register */

Restrictions

• You can use the

__sfrbit32

and

__sfrbit16

data type qualifiers only for int

types. The compiler issues an error if you use for example

__sfrbit32 char x : 8;

• When you use the

__sfrbit32

and

__sfrbit16

data type qualifiers for other types than a bit-field, the compiler ignores this without a warning. For example,

__sfrbit32 int global;

is equal to int global;

.

• Structures or unions that contain a member qualified with

__sfrbit16

, are zero padded to complete a halfword if necessary. The structure or union will be halfword aligned. Structures or unions that contain a member qualified with

__sfrbit32

, are zero padded to complete a full word if necessary. The structure or union will be word aligned.

1.3.3. Saturation: __sat

When a variable is declared with the type qualifier

__sat

, all operations on that variable will be performed using saturating arithmetic. When an operation is performed on a plain variable and a

__sat

variable, the

__sat

takes precedence, and the operation is done using saturating arithmetic. The type of the result of such an operation also includes the qualifier

__sat

, so that another operation on the result will also be saturated. In this respect, the behavior of the type qualifier

__sat

is comparable to the unsigned keyword. You can overrule this behavior by inserting type casts with or without the type qualifier

__sat in an expression.

You can only use the type qualifier

__sat

on type int

(fractional types are always saturated).

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