What is microprocessor LDTR?

Local Descriptor Table Register (LDTR) The LDTR register holds the 16-bit segment selector, base address (32 bits in protected mode; 64 bits in IA-32e. mode), segment limit, and descriptor attributes for the LDT. The base address specifies the linear address of byte.

What is LDTR and GDTR in microprocessor?

GDTR is the GDT (Global Descriptor Table) Register. It contains the base address (linear) and limit for the GDT, and is set using lgdt . LDTR is the LDT (Local Descriptor Table) Register and contains the linear base address and limit for the LDT.

What is the use of LDTR in 80386dx microprocessor?

Local Descriptor Table Register • LDTR is also a part of the memory management support mechanism. Each task can have access to its own private descriptor table in addition to the GDT. The private descriptor table is called LDT and defines a local memory address space for use by the task.

Which microprocessors contain an FS segment register?

The FS and GS segments are supplemental segment registers available in the 80386, 80486, Pentium. and Pentium Pro microprocessors to allow two additional memory segments for access by programs. The 80286 and above operate in either the real or protected mode. Only the 8086 and 8088 operate exclusively in the real mode.

What is the size of LDTR?

16 bits
LDT and TR: 16 bits, as every other segment register.

Is LDTR a segment selector?

LDTR: The LDTR register holds the 16-bit segment selector, 32-bit base address, 16-bit segment limit, and descriptor attributes for the LDT. The base address specifies the linear address of byte 0 of the LDT segment; the segment limit specifies the number of bytes in the segment.

What is use of LDTR IN 80386 microprocessor Mcq?

Explanation: The LDTR and TR are known as system segment registers. Explanation: Two test registers are provided by 80386 for page caching, namely test control and test status registers.

What is FS and GS register?

The registers FS and GS are segment registers. They have no processor-defined purpose, but instead are given purpose by the OS’s running them. In Windows 64-bit the GS register is used to point to operating system defined structures. FS and GS are commonly used by OS kernels to access thread-specific memory.

What is the EIP register?

The EIP register (prior to transferring program control) contains the address of the instruction following the CALL instruction. When this address is pushed on the stack, it is referred to as the return instruction pointer or return address.

What is the use of AX register?

AX is the primary accumulator; it is used in input/output and most arithmetic instructions. For example, in multiplication operation, one operand is stored in EAX or AX or AL register according to the size of the operand. BX is known as the base register, as it could be used in indexed addressing.

What is the use of LDTR?

Loads the source operand into the segment selector field of the local descriptor table register (LDTR). The source operand (a general-purpose register or a memory location) contains a segment selector that points to a local descriptor table (LDT).

What is size of LDTR?

Question What is the size of LDTR in 80386? A. 16 bits.