|
|||
| Products Download Events Support Videos | |||
Technical Support
On-Line Manuals
C166 User's Guide
C166 Introduction
Compiling Programs
Language Extensions
Keywords
Memory Models
Tiny Model
Small Model
Medium Model
Compact Model
Large Model
HCompact Model
HLarge Model
XLarge Model
Memory Types
near
far
bdata
ebdata
idata
sdata
huge
xhuge
Memory Type Comparison
Pointers with Memory Types
Implicit Memory Types
Type Qualifiers
const
volatile
Data Types
Special Function Registers
sfr Types
sbit Types
bit Types
Bit-Addressable Objects
Function Declarations
Return Values
Register Bank
Register Mask
Interrupt Functions
Fast Interrupts
Cached Vectors
Fast Register Banks
Inline Functions
Real-Time Function Tasks
Inline Assembly
Traditional Inline Assembly
Extended Inline Assembly
Operands
Operators
Register Use
Use in Macro Definitions
Preprocessor
Advanced Programming
Error Messages
Library Reference
Appendix
C166 User's Guide
Return Values
C functions (which are declared as follows) may return a single value with a specified type.
<[>type<]> funcname (<[>args<]>)
where:
| type | is the type of the value returned from the function. If no type is specified, int is assumed. |
| funcname | is the name of the function. |
| args | is the argument list for the function. |
Return values are always returned in registers depending on the return value type. The following table lists return types and the registers used for each.
| Return Type | Register(s) | Description |
|---|---|---|
| bit | R4.0 | |
| signed char unsigned char |
RL4 | |
| signed int unsigned int |
R4 | |
| signed long unsigned long |
R4-R5 | LSB in R4, MSB in R5. |
| float | R4-R5 | 32-bit IEEE format, exponent and sign in R5. |
| double | R4-R7 | 64-bit IEEE format, exponent and sign in R7. |
| near (2-byte) pointer | R4 | |
| far (4-byte) pointer huge (4-byte) pointer |
R4-R5 | Offset in R4, selector in R5. |
ProductsDevelopment Tools |
Hardware & Collateral |
Downloads |
Support |
Buy |
|
 |
|||
