High volume testing for USB electronic data flash cards
A high volume testing/formatting process is provided for Universal Serial Bus-based (USB-based) electronic data flash cards (USB devices) that meets the increasing demand for USB electronic data flash cards (USB devices). A test host is simultaneously coupled to the multiple USB devices (e.g., using a multi-port card reader or a probe fixture), a controller endpoint value is read from each of the USB devices and verified with a known good value, and then testing/formatting is performed on each of the USB devices by writing predetermined data into each USB device in a pipelined manner, then reading out and testing the predetermined data. In one embodiment, the test host implements a special a USB driver that blocks standard USB registration procedures upon detecting the plurality of USB devices. Control and/or boot code data are written onto the flash memory device (i.e., instead of being provided on a controller ROM).
1. A method for formatting/testing a plurality of USB devices using a test host, wherein each USB device including a controller and one or more flash memory devices, and the test host includes a computing system, the method comprising:
coupling all of said plurality of USB devices to the test host;
reading at least one controller endpoint descriptor value from each of the plurality of USB devices, and verifying that the controller endpoint descriptor values of each of the plurality of USB devices matches stored descriptor values stored in the test host; and
testing/formatting each of the USB devices having a valid endpoint descriptor value by writing predetermined data into the flash memory devices in a pipelined manner, and then reading the predetermined data from the flash memory device and comparing the read predetermined data with known good data stored in the test host.
2. The method according to claim 1 , further comprising installing a USB driver into the test host that directs the computing system to block standard USB registration procedures upon detecting the plurality of USB devices.
3. The method according to claim 1 , further comprising fabricating the plurality of USB devices such that the plurality of USB devices are connected to a panel.
4. The method according to claim 3 , further comprising singulating the panel before said coupling said USB devices to said test host.
5. The method according to claim 4 , wherein coupling all of said plurality of USB devices comprises plugging each of the plurality of USB devices into a corresponding port of a card reader, wherein the card reader is connected by a USB cable to the test host.
6. The method according to claim 3 , further comprising singulating the panel after sequentially testing/formatting all of said plurality of USB devices.
7. The method according to claim 6 , wherein coupling all of said plurality of USB devices to the test host comprises mounting a probe fixture onto the panel such that pins of each of the plurality of USB devices are contacted by corresponding probes of the probe fixture.
8. The method according to claim 1 , wherein said reading said controller endpoint descriptor values from each of the plurality of USB devices comprises reading at least one of a configuration descriptor value, a mass storage class code value, a vendor identification value, and a product identification value.
9. The method according to claim 1 , further comprising asserting a corresponding color flag displayed on a monitor of the test host upon verifying that the controller endpoint descriptor value stored in each of the plurality of USB devices matches said stored descriptor value.
10. The method according to claim 1 , wherein said testing/formatting comprises scanning bad block data stored in the flash memory device, and verifying that reserved storage capacity of each flash memory device is equal to a predetermined amount.
11. The method according to claim 1 , wherein said testing/formatting comprises writing at least two copies of bad block data identifying bad blocks on the flash memory device into predetermined blocks of the flash memory device.
12. The method according to claim 1 , wherein said testing/formatting comprises writing at least one of control code data and boot code data into predetermined blocks of the flash memory device.
13. The method according to claim 12 , wherein writing to the flash memory devices comprises transmitting predetermined data from the test host to a first buffer of a first USB device, and causing the first USB device to write the predetermined data from the first buffer into the flash memory device of the first USB device while the test host transfers the predetermined data to a second buffer of a second USE device.
14. The method according to claim 1 , wherein said sequentially testing/formatting comprises writing customer-provided data into predetermined blocks of the flash memory device.
15. The method according to claim 1 , wherein said sequentially testing/formatting comprises writing updated serial number, date code, and produce version code values into predetermined write-protected portions of the flash memory device.
16. A testing/formatting system for formatting/testing a plurality of electronic data flash cards using a test host, wherein each electronic data flash card including a controller and one or more flash memory devices, wherein the testing/formatting system comprises:
a test host;
means for coupling all of said plurality of electronic data flash cards to the test host;
means for reading at least one controller endpoint descriptor value from each of the plurality of electronic data flash cards, and for verifying that the controller endpoint descriptor values of each of the plurality of electronic data flash cards matches stored descriptor values; and
means for testing/formatting each of the electronic data flash cards having a valid endpoint descriptor value by writing predetermined data into the flash memory devices in a pipelined manner, and then reading the predetermined data from the flash memory device and comparing the read predetermined data with known good data.