Patent Application
20060168387
1. Field of the Invention
The present invention relates to a card reader with a peripheral component interconnect express (PCI Express), and more particularly to a card reader that uses the PCI Express as a transmission interface.
2. 2. Description of the Related Art
As the science and technology of computers grows in a fast changing manner, a computer tends to be developed with powerful computational functions and a fast speed, and thus the clock of a central processing unit (CPU) is too fast, and the transmission rate of other peripheral equipments cannot catch up with the processing speed of the CPU at all. Even though the CPU continues enhancing its performance, the transmission rate of peripheral equipments cannot be improved much because the overall performance of a computer depends on the whole system. It is necessary to improve the whole computer architecture before the performance of a CPU can be maximized.
However, the data transmission rate depends on the transmission rate of a bus. To enhance the performance of a computer, related manufacturers usually improve the transmission rate of a bus. For example, the transmission rate of an integrated drive electronic (IDE) interface connected to a hard disk drive reaches 160 MB/s; the network line is upgraded from 10 MB/s to 1 GB/s; the transmission rate of the RS-232 is replaced by the 480 MB/s of the universal serial bus (USB), and the present PCI with a transmission rate of 133 MB/s upgrades the transmission rate of its lane to 250 MB/s which is know as a new-generation peripheral component interconnect express (PCI Express). The PCI Express further supports a hot-plug control function. Therefore, the PCI Express is extensively accepted by users.
Further, The flash memory since its announcement gradually replaces the EEPROM or battery power memory in many portable device due to its charming features including low power consumption, non-volatility, shock resistance, and high-capacity storage. With the advanced semiconductor technologies, the storage capacity and transmission rate of a flash memory grow rapidly. The flash memory replaces traditional storage medium such as a hard disk drive in many applications; however, the present memory card made of flash memories has become an indispensable product to the general public due to the popularity of electric products such as digital cameras, PDAs and mobile phones, etc. The sales volume and the type of memory cards are growing, and most memory cards use a universal serial bus (USB) or integrated drive electronics (IDE) interface as the transmission interface. The transmission rates of the USB and IDE interface are just 480 MB/s and 160 MB/s respectively, and such transmission rate cannot catch up with the accessing speed of the memory card, so that the application of memory cards is restricted by the USB or IDE interface of the host and its performance cannot be maximized.
Therefore, it is desirable to provide a card reader that eliminates the aforesaid drawbacks.
The present invention has been accomplished under the circumstances in view. Therefore, it is a primary objective of the present invention to use the PCI Express bus as a transmission interface between a host and a card reader, so that the maximum transmission rate can be achieved when the host accesses data in the memory card through the card reader.
According to the foregoing objective, the card reader includes a microcontroller, and the microcontroller is coupled separately to a memory card interface for connecting a memory card and a PCI Express bus interface for connecting a PCI Express bus of a host, and the microcontroller has a memory card interface and a PCI Express bus interface, such that when the host saves or reads data in a memory card connected to the memory card interface, the memory card interface and PCI Express bus interface of the microcontroller converts the data into a data format acceptable to the memory card or the PCI Express bus, and then sends the converted data to the host or the memory card so as to meet the standard of the transmission rate of the PCI Express bus when the host accesses data in the storage device, and the transmission rate of the storage device can be maximized.
Referring to
The PCI Express connecting interface 11 is connected to a PCI Express 21 installed in a host 2.
The microcontroller 12 includes a memory card interface 121 and a PCI Express interface 122, and the microcontroller 12 is connected to the PCI Express connecting interface 11.
A memory card 13 is connected to the microcontroller 12, and the memory card interface 13 is provided for connecting the memory card 3.
If the PCI Express connecting interface 11 of the card reader 1 is connected to the PCI Express 21 of the host 2, then the microcontroller 12 of the card reader 1 will declare the memory card 1 as an endpoint device to the host 2. When the memory card 3 is connected to the memory card connecting interface 13, the host 2 can access data in the memory card 3.
When the host 2 transmits data to the memory card 3, the data in the host 2 is transmitted to the microcontroller 12 through the PCI Express 21 and the PCI Express connecting interface 11, and the memory card interface 121 of the microcontroller 12 converts the data into a data format acceptable to the memory card 3 and then save the data into the memory card 3 through the memory card connecting interface 13.
Further, if the host 2 intends to read data in the memory card 3, the memory card 3 will send the data to the micorcontroller 12 through the memory card connecting interface 13 first and the PCI Express interface 122 of the microcontroller 12 will convert the data into a data format acceptable to the PCI Express 21 and send the data to the host 2 through the PCI Express connecting interface 11 and the PCI Express 21.
The memory card interface 121 could be a CF memory card interface, a MS memory card interface, an XD memory card interface or a SD card interface. The quantity of memory card connecting interface 13 could be one or more.
Reference is made to
Therefore, the key technology for the card reader with PCI Express in accordance with the present invention to overcome the shortcoming of the prior arts resides on that the invention adopts the PCI Express as the interface between the host and the card reader, such that when the memory card connected to the card reader accesses data, the transmission rate can meet the standard of the PCI Express and thus the transmission rate of the card reader can be maximized.
A prototype of card reader with PCI Express has been constructed with the features of FIGS. 1˜2. The card reader with PCI Express functions smoothly to provide all of the features discussed earlier.
Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.
