Memory card operable with multiple host interfaces
A memory card has a plurality of pads including a first set of pads located to connect with host contacts arranged in a first configuration for communication according to the micro Secure Digital (microSD) standard, a second set of pads located to connect with host contacts arranged in a second configuration for communication according to the Peripheral Component Interface express (PCIe) protocol, and a third set of pads located to connect with host contacts arranged in a third configuration for communication according to the Universal Flash Storage (UFS) standard. The plurality of pads includes one or more common pads that are common to the second set of pads and the third set of pads.
1. A memory card, comprising:
a plurality of pads disposed on a surface of the memory card, the plurality of pads including:
a first set of pads located to connect with host contacts arranged in a first configuration for communication according to the micro Secure Digital (microSD) standard,
a second set of pads located to connect with host contacts arranged in a second configuration for communication according to the Peripheral Component Interconnect express (PCIe) protocol, and
a third set of pads located to connect with host contacts arranged in a third configuration for communication according to the Universal Flash Storage (UFS) standard, the plurality of pads including one or more common pads that are common to the second set of pads and the third set of pads; and
one or more circuits configured to detect connection to a UFS host.
2. The memory card of claim 1 wherein:
the first set of pads includes a plurality of microSD pads located a first distance from a leading edge of the memory card;
the second set of pads includes one or more dedicated PCIe pads located a second distance from the leading edge of the memory card;
the third set of pads includes one or more dedicated UFS pads located a third distance from the leading edge of the memory card; and
the common pads are elongated along a direction perpendicular to the leading edge of the memory card and extend between the first distance and the second distance.
3. The memory card of claim 2 wherein:
the plurality of microSD pads are arranged in a first row to engage with corresponding microSD host contacts;
the one or more dedicated PCIe pads are arranged in a second row to engage with corresponding PCIe host contacts;
the one or more dedicated UFS pads are arranged in a third row to engage with corresponding UFS host contacts; and
each of the common pads extends from the second row to the third row to engage with a corresponding PCIe host contact at a first location and with a corresponding UFS host contact at a second location.
4. The memory card of claim 1 wherein the common pads include one or more common pads configured to receive a constant voltage from a PCIe host contact and from a UFS host contact.
5. The memory card of claim 4 wherein the common pads include two or more common data pads configured to transfer data between the memory card and a PCIe host through PCIe host data contacts and between the memory card and a UFS host through UFS host data contacts.
6. The memory card of claim 5 wherein the two or more common data pads include:
a first pair of pads for receiving data through PCIe host data contacts or UFS host data contacts; and
a second pair of pads for sending data through PCIe host data contacts or UFS host data contacts.
7. The memory card of claim 5 wherein:
the first set of pads includes a plurality of microSD pads located a first distance from a leading edge of the memory card;
the second set of pads includes one or more dedicated PCIe pads located a second distance from the leading edge of the memory card, the one or more dedicated PCIe pads including a PCIe supply voltage pad;
the third set of pads includes one or more dedicated UFS pads located a third distance from the leading edge of the memory card, the one or more dedicated UFS pads including a UFS card detect pad; and
the common pads extend between the first distance and the second distance and include three common pads configured to receive a constant voltage and four common pads for data communication.
8. The memory card of claim 1 wherein the one or more common pads include a common pad configured to receive a clock signal in a UFS configuration and receive a power supply voltage in a PCIe configuration.
9. The memory card of claim 1 wherein:
the third set of pads includes a UFS card detect pad; and
the one or more circuits are further configured to detect a voltage provided by a host to the UFS card detect pad and connect the UFS card detect pad to ground in response to detecting connection to a UFS host.
10. The memory card of claim 1 wherein:
the third set of pads includes a UFS card detect pad; and
the one or more circuits are further configured to detect a current flowing from the card detect pad to ground.
11. The memory card of claim 1 wherein the one or more circuits are further configured to initiate communication using the UFS interface standard in response to detecting connection to a UFS host including configuring two pairs of common pads for UFS data communication.
12. The memory card of claim 1 wherein the memory card has a form factor of a microSD card or of a UFS card.
13. The memory card of claim 1 wherein the plurality of pads includes one or more power supply pads that are common to the first set, the second set, and the third set of pads.
14. A method comprising:
determining whether a host that is connected to a memory card operable with multiple host interface standards is configured to use the Universal Flash Storage (UFS) interface standard;
in response to determining that the host is configured to use the UFS interface standard, configuring an interface circuit of the memory card for UFS communication; and
in response to determining that the host is not configured to use the UFS interface standard;
determining whether the host is configured to use the Peripheral Component Interconnect express (PCIe) interface protocol;
in response to determining that the host is configured to use the PCIe interface protocol, configuring the interface circuit of the memory card for PCIe communication; and
in response to determining that the host is not configured to use the PCIe interface protocol, configuring the interface circuit of the memory card for communication using the micro Secure Digital (microSD) interface standard.
15. The method of claim 14 , wherein determining whether the host is configured to use the UFS interface standard includes:
detecting a voltage on a UFS card detect pad; and
in response to detecting connection to a UFS host, connecting the card detect pad to ground.
16. The method of claim 14 wherein determining whether the host is configured to use the UFS interface standard includes detecting a current flowing from the card detect pad to ground.
17. The method of claim 14 wherein:
configuring the interface circuit of the memory card for UFS communication includes configuring the interface circuit to receive a clock signal on a common pad; and
configuring the interface circuit of the memory card for PCIe communication includes configuring the interface circuit to receive a power supply voltage on the common pad.
18. A memory card, comprising:
a first surface configured to engage a host;
a plurality of pads disposed on the first surface, the plurality of pads including:
a first set of pads located along a first row to connect with host contacts arranged in a first configuration for communication according to the micro Secure Digital (microSD) standard,
a second set of pads located along a second row to connect with host contacts arranged in a second configuration for communication according to a high-speed interface protocol, and
a third set of pads located along a third row to connect with host contacts arranged in a third configuration for communication according to the Universal Flash Storage (UFS) standard, the third set of pads including a plurality of common pads that are common to the second set of pads and that extend across the second and third rows to connect with host contacts arranged in the second configuration or the third configuration; and
means for detecting connection of the memory card to a UFS host via the plurality of pads.
19. The memory card of claim 18 further comprising means for configuring interface circuits connected to the plurality of pads for communication according to the UFS interface standard for communication with a UFS host, for communication according to the high-speed interface protocol for communication with a high-speed host, and for communication according to the microSD standard for communication with a microSD host.
20. The memory card of claim 18 wherein the high-speed interface protocol is one of Peripheral Component Interconnect express (PCIe) protocol or Ultra High Speed-II (UHS-II) protocol.