Secure-Digital (SD) Flash Card with Auto-Adaptive Protocol and Capacity

An adaptive-version controller chip comprising:

• a flash bus for connecting to a flash-memory chip, the flash bus carrying address, data, and commands to the flash-memory chip;
• a clocked-data interface to a host bus that connects to a host having a protocol version;
• a bus transceiver for detecting and processing commands sent over the host bus;
• a buffer for storing data sent over the host bus;
• an internal bus coupled to the buffer;
• a random-access memory (RAM) for storing instructions for execution, the RAM on the internal bus;
• a central processing unit (CPU), on the internal bus, the CPU accessing and executing instructions in the RAM;
• a flash-memory controller, on the internal bus, for generating flash-control signals and for buffering commands, addresses, and data to the flash bus;
• a direct-memory access (DMA) engine, on the internal bus, for transferring data over the internal bus;
• and
• an initialization routine, executed by the CPU to receive commands from the host through the bus transceiver, and for sending replies to the host, the initialization routine detecting the protocol version of the host and setting a version mode that the adaptive-version controller chip operates with,
• whereby the protocol version is detected by the initialization routine.

A dual-version flash drive comprising:

• a flash-memory means for storing blocks of data in a non-volatile memory that retains data when power is lost;
• a first area of the flash-memory means, for storing data for a standard-capacity host;
• a second area of the flash-memory means, for storing data for a high-capacity host;
• wherein the second area is larger than the first area;
• a Secure Digital (SD) interface that connects to a host over a SD host bus;
• protocol interface means for extracting host commands from host transactions received over the SD host bus from the host;
• flash memory manager means for translating addresses in the host commands to physical addresses of blocks within the flash-memory means;
• flash interface means for generating erase, write, and read commands of blocks in the flash-memory means using the physical addresses from the flash memory manager means;
• version-detect means, activated when the dual-version flash drive is connected to the host, for detecting a version of the host;
• standard configuration means for configuring the flash-memory manager means to access the first area of the flash-memory means and to disable access to the second area of the flash-memory means when the version-detect means detects that the host has a version for the standard-capacity host;
• high configuration means for configuring the flash-memory manager means to access the second area of the flash-memory means and to disable access to the first area of the flash-memory means when the version-detect means detects that the host has a version for the high-capacity host,
• whereby access to the first area of the flash-memory means is enabled for the standard-capacity host, and disabled for the high-capacity host, while access to the second area of the flash-memory means is enabled for the high-capacity host, and disabled for the standard-capacity host.