Texas Instruments MSP-FET430 manual Frequently Asked Questions, TXT format

Frequently Asked Questions

9)It is possible to mix assembler and C programs within the Workbench. Refer to the Assembler Language Interface chapter of the C/C++ Compiler Reference Guide from IAR.

10)The Workbench can produce an object file in Texas Instruments .TXT format. C-SPY cannot input an object file in Texas Instruments

.TXT format.

11)The example programs giving in the Kickstart documentation (i.e., Demo, Tutor, etc.) are not correct. The programs will work only in the simulator. However, the programs will not function correctly on an actual device because the Watchdog mechanism is active. The programs need to be modified to disable the Watchdog mechanism. Disable the Watchdog mechanism with the C-statement: “WDTCTL = WDTPW + WDTHOLD;”, or “mov #5a80h,&WDTCTL” in assembler.

12)Access to MPY using an 8-bit operation is flagged as an error. Within the .h files, 16-bit registers are defined in such a way that 8-bit operations upon them are flagged as an error. This “feature” is normally a good thing and can catch register access violations. However, in the case of MPY, it is also valid to access this register using 8-bit operators. If 8-bit operators are used to access MPY, the access violation check mechanism can be defeated by using “MPY_” to reference the register. Similarly, 16-bit operations on 8-bit registers are flagged.

13)Constant definitions (#define) used within the .h files are effectively “reserved”, and include, for example, C, Z, N, and V. Do not create program variables with these names.

14)The CSTARTUP that is implicitly linked with all C applications does not disable the Watchdog timer. Use WDT = WDTPW + WDTHOLD; to explicitly disable the Watchdog. This statement is best placed in the __low_level_init() function that gets executed before main().

If the Watchdog timer is not disabled and the Watchdog triggers and resets the device during CSTARTUP, the source screen will go blank as C-SPY is not able to locate the source code for CSTARTUP. Be aware that CSTARTUP can take a significant amount of time to execute if a large number of initialized global variables are used.

int __low_level_init(void)

{

/* Insert your low-level initializations here */

WDTCTL = WDTPW + WDTHOLD; // Stop Watchdog timer

/*==================================*/

/* Choose		if	segment		initialization */
/* should		be	done or		not.	*/
/*	Return: 0		to	omit	seg_init	*/
/*		1	to	run seg_init		*/

/*==================================*/ return (1);

}

15)Compiler optimization can remove unused variables and/or statements that have no effect, and can effect debugging.

A-4