Assembler Directives

The assembly process can be controlled by assembler directives. The assembler interprets the assembler directives instead of translating them into machine instructions. The assembler supports the following directives:

Directive

Description

ORG <address>

Assemble the subsequent source statements starting at the specified address, <address>.

Examples:

ORG 1123H ; Start assembling at address 4387
ORG 567o ; Start assembling at address 375

DB <number>

Store the specified 1-byte constant <number> in memory.

Examples:

DB 11 ; Store the 8-bit constant 11 in memory
DB 333o ; Store the 8-bit constant 219 in memory

DW <number>

Store the specified 2-byte constant <number> in memory. The assembler initializes the memory with the least significant byte first.

Examples:

DW 23785 ; Store the 16-bit constant 23785 in memory
DW af43h ; Store the 16-bit constant 44867 in memory

Assembler Labels

The assembler also supports jump to lables of the form label_name: (notice the : after the label name). The labels are not case censetive.

Example:

JMP MyLabel

....

MyLabel: ....