What is the 68000 processor addressing modes?
The 68020, 68030, 68040 processors have 32 external address lines as well as 32 data lines. Addressing : The memory of a 68000 computer is organized in 16-bit words and is byte-addressable. Two consecutive words can be interpreted as a single 32-bit long word.
What are the five assembler directives?
Reserve space in memory for uninitialized variables. Control the appearance of listings. Initialize memory. Assemble conditional blocks.
What is assembler directives with example?
Directives are instructions used by the assembler to help automate the assembly process and to improve program readability. Examples of common assembler directives are ORG (origin), EQU (equate), and DS. B (define space for a byte). Machine instructions generate machine code, assembler directives do not.
How many assembler directives are there?
There are 4 assembler directives and the comment tag.
How many addressing modes does the Motorola 68000 have?
12 modes
There are 12 modes in 68000 and 18 modes in 68020-68040.
How many classes of registers does the 68000 have?
8
The Motorola 68000 processor has 18 registers that are directly accessible by the user. Those are: 8 general-purpose data registers numbered from D0 to D7. 8 address registers numbered from A0 to A7.
What are assembler directives list out any five assembler directives in SIC?
Assembler directives (or pseudo opcodes): START, END, BYTE, WORD, RESB, RESW, BASE and NOBASE.
Is end an assembler directive?
12.24 END. The END directive informs the assembler that it has reached the end of a source file.
How many registers are there in an assembler?
Edit multiple files. Many assembler directives (DC, DS, EQU, INCLUDE, OFFSET, SECTION etc.) Creates S-Record and binary files. Displays: 68000 registers, source code, stack, memory, hardware and output results.
What is the size of a 68000 user register?
The 68000 User Registers Here are the important points you should know about the 68000 user registers: All the data registers, all the address registers and the Program Counter are 32-bits (4 bytes) wide. The Status Register, or SR, is 16 bits (2 bytes) wide.
Is the memory of the 68000 microcontroller bit addressable?
The memory is said to be byte-addressable, i.e. each byte within the memory has its own unique address and can be accessed directly. Note that the memory of the 68000 is not bit-addressable, which means that you cannot access data in memory bit by bit.
What is the size of the 32 bit address in 68000?
The 32 bit addresses are given as 8 hexadecimal digits. As you know, the 68000 has a 32 bit Program Counter and 32 bit address registers. This is so because addresses of locations in memory are 32 bit numbers, and consequently you can address up to 2 32 locations, i.e. 2 32 bytes, or 4 gigabytes (each memory location is one byte).
