Texas Instruments MSP-FET430 manual E.2.3 Section Control Directives

TI to IAR 2.x/3.x Assembler Migration

consecutive backslashes (\\). In Asm430 syntax, a quote is represented by two consecutive quotes (“”). See examples below:

Character String	Asm430 Syntax (TI)	A430 Syntax (IAR)
PLAN “C”	“PLAN “”C”””	“PLAN \”C\””
\dos\command.com	“\dos\command.com”	“\\dos\\command.com”
Concatenated string (i.e. Error 41)	-	“Error ” “41”

E.2.3 Section Control Directives

Asm430 has three predefined sections into which various parts of a program are assembled. Uninitialized data is assembled into the .bss section, initialized data into the .data section and executable code into the

.text section.

A430 also uses sections or segments, but there are no predefined segment names. Often, it is convenient to adhere to the names used by the C compiler: DATA16_Z for uninitialized data, CONST for constant (initialized) data and CODE for executable code. The table below uses these names.

A pair of segments can be used to make initialized, modifiable data PROM- able. The ROM segment would contain the initializers and would be copied to RAM segment by a start-up routine. In this case, the segments must be exactly the same size and layout.

Description	Asm430 Directive (TI)	A430 Directive (IAR)
Reserve size bytes in the .bss	.bss	1)
(uninitialized data) section
Assemble into the .data (initialized data)	.data	RSEG const
section
Assemble into a named (initialized)	.sect	RSEG
section
Assemble into the .text (executable code)	.text	RSEG code
section
Reserve space in a named (uninitialized)	.usect	1)
section
Alignment on byte boundary	.align	2)
Alignment on word boundary	.even	EVEN

1)Space is reserved in an uninitialized segment by first switching to that segment, then defining the appropriate memory block, and then switching back to the original segment. For example:

RSEG DATA16_Z

LABEL: DS 16

RSEG CODE

2)Initialization of bit-field constants (.field) is not supported, therefore, the section counter is always byte- aligned.

Additional A430 Directives (IAR)	A430 Directive (IAR)
Switch to an absolute segment	ASEG
Switch to a relocatable segment	RSEG
Switch to a common segment	COMMON
Switch to a stack segment (high-to-low allocation)	STACK
Alignment on specified address boundary (power of two)	ALIGN
Set the location counter	ORG

E-3