14.1.1 Specifying a Memory Model
The Cmacro memory-model options specify the memory model that the application will use. The memory model defines how many code and data segments are in the application. Following is a list of the possible memory models:
| Small |
One code segment and one data segment |
| Medium |
Multiple code segments and one data segment |
| Compact |
One code segment and multiple data segments |
| Large |
Multiple code and data segments |
| Huge |
Multiple code segments and multiple data segments, with one or more data items larger than 64K |
Select a memory model by defining the option name at the beginning of the assembly-language source file. These option names are available:
| Option name |
Memory model |
Code size |
Data size |
| memS |
Small |
Small |
Small |
| memM |
Medium |
Large |
Small |
| memC |
Compact |
Small |
Large |
| memL |
Large |
Large |
Large |
| memH |
Huge |
Large |
Large |
You can define a name by using the EQU directive. The definition has the following form:
memM EQU 1
If no option is selected, the default model is small.
When you select a memory-model option, two symbols are defined: SizeC and SizeD. These two symbols can be used for code that is dependent on the memory model. They can have the following values:
| SizeC |
0 |
Small code |
| |
1 |
Large code |
| SizeD |
0 |
Small data |
| |
1 |
Large data |
| |
2 |
Huge data |