Patent ID: 7870349

Claim:
A method for accessing a memory, comprising: receiving a memory accessing command, wherein the memory accessing command requests for accessing a memory block in a memory of a system corresponding to an address space occupied by a memory-mapped input output (MMIO) function; entering a memory accessing mode for updating a top of low memory (TOLM) value stored in a TOLM register in a chipset of the system with a highest address of the memory, comprising obtaining a basic address of an I/O advanced programmable interrupt controller (IO APIC) in the chipset of the system; comparing the highest address and the basic address; writing the basic address into the TOLM register when the highest address is larger than or equal to the basic address; and writing the highest address into the TOLM register when the highest address is less than the basic address; accessing the corresponding memory block in the memory according to the address space recorded in the memory accessing command; and closing the memory accessing mode and writing the original TOLM value back to the TOLM register.