Flashtoaster for Reading Several Types of Flash-Memory Cards, With or Without a PC
A flash-memory-card reader reads and writes multiple types of flash-memory cards, including CompactFlash, and the smaller SmartMedia, MultiMediaCard, Secure Digital, and Memory Stick. A converter chip converts the different card signals for transfer to a host personal computer (PC). Serial-to-parallel data conversion is performed for the smaller card formats with serial data interfaces, but not for CompactFlash with a parallel-data interface. A single slot has a 50-pin connector for CompactFlash cards or passive adapters. The passive adapters have the CompactFlash form factor and a smaller connector fitting smaller flash cards. Passive adapters have no components but simply wire the smaller connector to the CompactFlash connector. A pin mapping allows card-type detection by sensing the LSB address pins of the CompactFlash interface. A larger CompactFlash reader has multiple slots for each card type. The reader is connected to the PC by a cable, or located within the PC chassis in a drive bay. A stand-alone reader copies images from the flash-memory card to a removable disk media. Pressing a button initiates image transfer.
1 . A memory card reader comprising:
a first card slot configured to receive memory card of a first format having a first size;
a controller coupled to the first card slot, the controller to detect a card of a first format inserted in the first slot and the controller to read data from the card of the first format, and the controller to detect a card of a second format inserted in the first slot and the controller to read data from the card of the second format, wherein the controller is to identify the format of the card by reading a first card select pin and a second card select pin.
2 . The memory card reader of claim 1 , wherein the second format has a smaller pin count relative to the first format.
3 . The memory card reader of claim 2 , wherein the first card format is a CompactFlash (CF) card.
4 . The memory card reader of claim 1 , wherein the second card format is one of a group comprising of Multimedia Card (MMC), Secure Digital (SD), and Memory Stick.
5 . The memory card reader of claim 4 :
wherein the first and second card select pins are high when the card format is CF;
wherein the first card select pin is low and the second card select pin is high when the card format is MMC or SD; and
wherein the first and second card select pins are low when the card format is Memory Stick.
6 . The memory card reader of claim 1 , further comprising: an adapter to physically adapt the card to interface with the first card slot, when the card is other than the first format.
7 . The memory card reader of claim 6 , wherein the adapter is a passive adapter.
8 . The memory card reader of claim 1 , further comprising:
a first pull-up resistor coupled between the first card select pin and the controller;
a second pull-up resistor coupled between the second card select pin and the controller;
wherein the pull-up resistors drive the card select pins high when no pin from the card format is present.
9 . A controller comprising:
an interface to communicate with a first card slot;
a unit to detect a card of a first format inserted in the first slot and to read data from the card of the first format, and to detect a card of a second format inserted in the first slot and to read data from the card of the second format, wherein the controller is to identify the format of the card by reading a first card select pin and a second card select pin.
10 . The controller of claim 9 , wherein the second format has a smaller pin count relative to the first format.