Texas Instruments MSP-FET430 E.1 Segment Control, E.2.1 Introduction, E.2.2 Character strings

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

E.1 Segment Control

RSEG defines a Relocatable SEGment. A relocatable segment means that the code that follows the RSEG statement will be place *somewhere* in the region defined for that segment (in the .xcl file). In other words, the code can be "relocated", and you don't know (or care) where it's put. In the .xcl files provided with the FET, multiple segments are defined in the same memory regions. ASEG defines an Absolute SEGment. An absolute segment means that the code that follows the ASEG statement will be placed in the order it is encountered in the region defined for the segment (in the .xcl file). In other words, the placement of the code is fixed in memory. One significant difference between the new IAR assembler and the old TI assembler is the meaning of the ORG statement. In the old TI assembler, ORG would set the assembler code pointer to the specified absolute address. However, the IAR assembler uses ORG to set an offset from the current RSEG. Fortunately, if you don't use RSEG explicitly, it will default to 0 (zero) and your program will link as you expect (with your code at ORG). Be careful if you mix RSEG and ORG as ORG then becomes a relative offset. Use ASEG if you want the (absolute) behavior of the old TI ORG statement.

E.2 Translating Asm430 Assembler Directives to A430 Directives

E.2.1 Introduction

The following sections describe, in general, how to convert assembler directives for Texas Instruments’ Asm430 assembler (Asm430) to assembler directives for IAR’s A430 assembler (A430). These sections are only intended to act as a guide for translation. For detailed descriptions of each directive, refer to either the MSP430 Assembly Language Tools User’s Guide, SLAUE12, from Texas Instruments, or the MSP430 Assembler User’s Guide from IAR.

Note: Only the assembler directives require conversion

Only the assembler directives require conversion - not the assembler instructions. Both assemblers use the same instruction mnemonics, operands, operators, and special symbols such as the section program counter ($), and the comment delimiter (;).

The A430 assembler is not case sensitive by default. These sections show the A430 directives written in uppercase to distinguish them from the Asm430 directives, which are shown in lower case.

E.2.2 Character strings

In addition to using different directives, each assembler uses different syntax for character strings. A430 uses C syntax for character strings: A quote is represented using the backslash character as an escape character together with quote (\”) and the backslash itself is represented by two

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