Keil C Segment 命名规则

Segment Naming Conventions

Objects generated by the Cx51 Compiler (program code, program data, and constant data) are stored in segments which are units of code or data memory. A segment may be relocatable or may be absolute. Each relocatable segment has a type and a name. This section describes the conventions used by the Cx51 Compiler for naming these segments.

Segment names include a module_name which is the name of the source file in which the object is declared. In order to accommodate a wide variety of existing software and hardware tools, all segment names are converted and stored in uppercase.

Each segment name has a prefix that corresponds to the memory type used for the segment. The prefix is enclosed in question marks (?). The following is a list of the standard segment name prefixes:

 

Segment Prefix	Memory Type	Description
?PR?	program	Executable program code
?CO?	code	Constant data in program memory
?BI?	bit	Bit data in internal data memory
?BA?	bdata	Bit-addressable data in internal data memory
?DT?	data	Internal data memory
?FD?	far	Far memory (RAM space)
?FC?	const far	Far memory (constant ROM space)
?ID?	idata	Indirectly-addressable internal data memory
?PD?	pdata	Paged data in external data memory
?XD?	xdata	Xdata memory (RAM space)
?XC?	const xdata	Xdata memory (constant ROM space)

The segment name is assigned based on the memory model of the function.

Small Model Segment Naming Conventions

 

Information	Segment Type	Segment Name
Program code	code	?PR?function_name?module_name
Local variables	data	?DT?function_name?module_name
Local bit variables	bit	?BI?function_name?module_name

Compact Model Segment Naming Conventions

 

Information	Segment Type	Segment Name
Program code	code	?PR?function_name?module_name
Local variables	pdata	?PD?function_name?module_name
Local bit variables	bit	?BI?function_name?module_name

Large Model Segment Naming Conventions

 

Information	Segment Type	Segment Name
Program code	code	?PR?function_name?module_name
Local variables	xdata	?XD?function_name?module_name
Local bit variables	bit	?BI?function_name?module_name

reference: http://www.keil.com/support/man/docs/c51/c51_ap_segname.htm