Texas Instruments MSP-FET430, User Manual

Page: 83 / 95

TI to IAR 2.x/3.x Assembler Migration
E-3
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
(uninitialized data) section .bss 1)
Assemble into the .data (initialized data)
section .data RSEG const
Assemble into a named (initialized)
section .sect RSEG
Assemble into the .text (executable code)
section .text RSEG code
Reserve space in a named (uninitialized)
section .usect 1)
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