Apparatus and Method to Share Host System RAM with Mass Storage Memory RAM

Abstract

A method includes, in one non-limiting embodiment, sending a request from a mass memory storage device to a host device, the request being one to allocate memory in the host device; writing data from the mass memory storage device to allocated memory of the host device; and subsequently reading the data from the allocated memory to the mass memory storage device. The memory may be embodied as flash memory, and the data may be related to a file system stored in the flash memory. The method enables the mass memory storage device to extend its internal volatile RAM to include RAM of the host device, enabling the internal RAM to be powered off while preserving data and context stored in the internal RAM.

What is claimed is: 
     
         1 . A method, comprising:
 in response to an allocation of read/write memory in a host device for use by a mass memory storage device, writing data from the mass memory storage device to the allocated read/write memory of the host device; and   subsequently reading the data from the allocated memory to the mass memory storage device.   
     
     
         2 . The method of  claim 1 , where the data comprises meta-data associated with a file system stored in a non-volatile memory of the mass memory storage device. 
     
     
         3 . The method of  claim 1 , where writing data is followed by removing power from a volatile memory of the mass memory storage device. 
     
     
         4 . The method of  claim 1 , further comprising, at the completion of reading the data, sending a request from the mass memory storage device to the host device, the request being one to de-allocate the read/write memory in the host device. 
     
     
         5 . The method of  claim 1 , performed as a result of execution of computer program instructions by a controller of the mass memory storage device, and where the allocation is made in response to a request sent from the mass memory storage device to the host device. 
     
     
         6 . An apparatus, comprising:
 a controller;   a volatile memory that is readable and writable by the controller;   a non-volatile memory that is readable and writable by the controller; and   an interface for connecting the apparatus to a host device.   said controller being configurable to respond to an allocation of read/write memory in the host device to write data to the allocated memory of the host device and to subsequently read the data from the allocated memory.   
     
     
         7 . The apparatus of  claim 6 , where the data comprises meta-data associated with a file system stored in the non-volatile memory of the mass memory storage device. 
     
     
         8 . The apparatus of  claim 6 , where writing data is followed by removing power from the volatile memory of the mass memory storage device, and where the allocation is made in response to a request sent from the controller to the host device via the interface. 
     
     
         9 . The apparatus of  claim 6 , said controller being further configurable, at the completion of reading the data, to send a request to the host device, the request being one to de-allocate the read/write memory in the host device. 
     
     
         10 . The apparatus of  claim 6 , where said non-volatile memory is comprised of flash memory. 
     
     
         11 . A method, comprising:
 allocating read/write memory in a host device for use by a mass memory storage device;   receiving data from the mass memory storage device and writing the received data into the allocated read/write memory of the host device; and   subsequently sending the data from the allocated memory to the mass memory storage device.   
     
     
         12 . The method of  claim 11 , where the data comprises meta-data associated with a file system stored in a non-volatile memory of the mass memory storage device. 
     
     
         13 . The method of  claim 11 , further comprising processing the data in the host device. 
     
     
         14 . The method of  claim 13 , where processing comprises at least one of sorting, arranging and filtering the data. 
     
     
         15 . The method of  claim 11 , further comprising, at the completion of sending the data, receiving a request from the mass memory storage device, the request being one to de-allocate the allocated memory. 
     
     
         16 . The method of  claim 11 , performed as a result of execution of computer program instructions by a controller of the host device, and where the allocation is made by the controller in response to one of an allocation request received by the host device or at the initiative of the host device. 
     
     
         17 . An apparatus, comprising:
 a controller;   a memory that is readable and writable by the controller; and   an interface for connecting the apparatus to a mass storage memory device;   said controller being configurable to allocate a portion of the memory for use by the mass storage memory device, said controller being further configurable to receive data from the mass storage memory device and to store the received data in the allocated portion of the memory and to subsequently send the data from the allocated portion of the memory to the mass storage memory device.   
     
     
         18 . The apparatus of  claim 17 , where the data comprises meta-data associated with a file system stored in a non-volatile memory of the mass memory storage device. 
     
     
         19 . The apparatus of  claim 17 , said controller being further configurable to process the data received from the mass memory storage device before sending the data from the allocated portion of the memory to the mass storage memory device. 
     
     
         20 . The apparatus of  claim 19 , where said controller when processing the data performs at least one of sorting, arranging and filtering the data.