5.7.4.2 xc-dsc-gcc - Memory Model Category

Table 5-6. Memory Model Options
Option	Description	Command Line
Code model	Select a code (program memory/ROM) model. - default - large (>32 K words) - small (<32 K words)	`-msmall-code` `-mlarge-code` `-msmall-code`
Data model	Select a data (data memory/RAM) model. - default - large (device dependent¹) - small (device dependent¹)	device dependant² `-mlarge-data` `-msmall-scalar`
Scalar model	Select a scalar model. - default - large (device dependent¹) - small (device dependent¹)	`-msmall-scalar` `-mlarge-scalar` `-msmall-scalar`
Location of constant model	Select a memory location for constants. - default - Data - Code	`-mconst-in-code` `-mconst-in-data` `-mconst-in-code`
Place all code in auxiliary flash	Place all code from the current translation unit into auxiliary Flash. This option is only available on devices that have auxiliary Flash.	`-mauxflash`
Put constants into auxiliary flash	When combined with -mconst-in-code, put constants into auxiliary Flash.	`-mconst-in-auxflash`
Allow arrays larger than 32K	Allow arrays that are larger than 32K, regardless of memory model.	`-menable-large-arrays`
Aggregate data model	Use aggregate data model.	`-mlarge-aggregate`
Note: For most devices 6K of RAM is the near data space, but for some devices it is 4K of RAM. For devices that have all of their data memory in the near space, the memory model is "small data" "small scalar" so that all memory will be allocated in the near space. For all other devices the default memory model is "large data" "small scalar." This will have the effect of allowing the tool chain to place aggregate objects, such as arrays and structure, into the far memory space. This can be over-ridden by explicitly selecting "small data" in the compiler options.

Code model

Select a code (program memory/ROM) model.

- default

- large (>32 K words)

- small (<32 K words)

-msmall-code

-mlarge-code

-msmall-code

Data model

Select a data (data memory/RAM) model.

- default

- large (device dependent¹)

- small (device dependent¹)

device dependant²

-mlarge-data

-msmall-scalar

Scalar model

Select a scalar model.

- default

- large (device dependent¹)

- small (device dependent¹)

-msmall-scalar

-mlarge-scalar

-msmall-scalar

Location of constant model

Select a memory location for constants.

- default

- Data

- Code

-mconst-in-code

-mconst-in-data

-mconst-in-code

Place all code in auxiliary flash

Place all code from the current translation unit into auxiliary Flash. This option is only available on devices that have auxiliary Flash.

-mauxflash

Put constants into auxiliary flash

When combined with -mconst-in-code, put constants into auxiliary Flash.

-mconst-in-auxflash

Allow arrays larger than 32K

Allow arrays that are larger than 32K, regardless of memory model.

-menable-large-arrays

Aggregate data model

Use aggregate data model.

-mlarge-aggregate

Note:

For most devices 6K of RAM is the near data space, but for some devices it is 4K of RAM.
For devices that have all of their data memory in the near space, the memory model is "small data" "small scalar" so that all memory will be allocated in the near space.
For all other devices the default memory model is "large data" "small scalar." This will have the effect of allowing the tool chain to place aggregate objects, such as arrays and structure, into the far memory space. This can be over-ridden by explicitly selecting "small data" in the compiler options.