tailieunhanh - Đề thi sát hạch kỹ sư công nghệ thông tin part 6

Line type Description format Instruction With operand [label]{blank}{instruction code}{blank}{operand}[{blank}[comment]] line Without operand [label]{blank}{instruction code}[{blank}[{;}[comment] ] ] Comment line [blank]{;}[comment] (Note) [ ] Square brackets ([ ]) indicate that the specification contained in the brackets may be omitted. { } Braces ({ }) indicate that the specification contained in the braces is mandatory. Label Label is the name used to refer to the address of (the first word of) the instruction from other instructions and programs. A label must be 1. | 2 Specifications of the CASL II Assembly Language Specifications of the language 1 CASL II is an assembly language for the COMET II. 2 A program consists of instruction lines and comment lines. 3 One instruction is described in one instruction line and cannot continue to the next line. 4 Instruction lines and comment lines are written from the first character of the line in the following description formats Line type Description format Instruction With operand label blank instruction code blank operand blank comment line Without operand label blank instruction code blank comment Comment line blank comment Note Square brackets indicate that the specification contained in the brackets may be omitted. Braces indicate that the specification contained in the braces is mandatory. Label Label is the name used to refer to the address of the first word of the instruction from other instructions and programs. A label must be 1 to 8 characters in length and the leading character must be an uppercase alphabetic letter. Either uppercase alphabetic letters or numeric characters can be used for the subsequent characters. Reserved words GR0 through GR7 are not available. Blank One or more space characters. Instructio The description format is defined by instruction. n code tạo Operand The description format is defined by instruction. Comment Optional information such as memorandums that can be written in any characters allowed by the processing system. Instruction Types CASL II consists of four assembler instructions START END DS and DC four macro instructions IN OUT RPUSH and RPOP and machine language instructions COMET II instructions . The specifications are as follows Instruction type Label Instruction code Operand Function Assembler instruction Label START Execution start address Defines the top of a program. Defines the starting address for execution of a program. Defines the entry name for .