Texas Instruments MSP50C614 manual Assembler

Assembler

BYTE expression[,expression]: Introduces one or more data items, of BYTE size (8 bits) . The bytes are placed in the program memory in the order in which they are declared.

CHIP_TYPE chip_name: This directive is here for compatibility with future chips in the same family. It defines some chip parameters (like RAM and ROM size) for the assembler. For now, the only defined chip names are MSP50P614/MSP50C614 and MSP50P614/MSP50C614.

DATA expression[,expression]: Introduces one or more data items, of WORD size (16 bits) . The words are placed in the program memory in the order in which they are declared. Even though the program memory is 17 bits wide, only 16 bits can be read using assembly instructions (like MOV A0,*A0), so the DATA directive only stores 16 bits per data expression.

DB expression[,expression]: Equivalent to BYTE directive

DEF symbol[,symbol]: Equivalent to GLOBAL directive

DW expression[,expression]: Equivalent to DATA directive

END expression: Expression defines the start±up vector for the current assembly program. This directive generates the following assembly code;

AORG 0xFFFF

DATA expression

which defines the start-up vector of the program, i.e., the program address where execution starts following INIT of the chip.

label EQU expression: Associates the value of expression with label.

EXTERNAL symbol[,symbol]: This directive is used to indicate to the assembler that one or more symbols are external references, i.e., symbols that will be resolved by the linker.

GLOBAL symbol[,symbol]: This directive is used to indicate to the assembler that one or more symbols are global references. These symbols MUST be defined in the current file, and will be used by the linker to resolve external references (present in other files). GLOBAL should only be used for PROGRAM labels. RAM variables are handled with the GLOBAL_VAR directive.

GLOBAL_VAR symbol[,symbol]: This directive can be used to allow for RAM variables to be referenced in a different file from where they were defined. GLOBAL_VAR should be used prior to defining a RAM variable (with the RESW directive, for example). The variable to be referenced in another file

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