SanDisk SD032 Handbuch PDF herunterladen (Seite 11)

1.5.6. Using the Erase Command

The Erase (sector or group) command provides the capability to substantially increase the write performance of the

miniSD Card. Once a sector has been erased using the Erase command, a write to that sector will be much faster.

This is because a normal write operation includes a separate sector erase prior to write.

1.5.7. Automatic Sleep Mode

A unique feature of the SanDisk miniSD Card (and other SanDisk products) is automatic entrance and exit from

sleep mode. Upon completion of an operation, the miniSD Card will enter the sleep mode to conserve power if no

further commands are received within 5msec. The host does not have to take any action for this to occur. In most

systems, the miniSD Card is in sleep mode except when the host is accessing it, thus conserving power.

When the host is ready to access the miniSD Card and it is in sleep mode, any command issued to the miniSD Card

will cause it to exit sleep and respond.

1.5.8. Hot Insertion

Support for hot insertion will be required on the host but will be supported through the connector. Connector

manufacturers will provide connectors that have power pins long enough to be powered before contact is made with

the other pins. Please see connector data sheets for more details. This approach is similar to that used in PCMCIA

and MMCA devices to allow for hot insertion.

1.5.9. miniSD—SD Bus Mode

The following sections provide valuable information on the SC Card in SD Bus mode.

1.5.9.1. miniSD Standard Compliance

The miniSD Card is fully compliant with mini SD Physical Layer Standard Specification V1.02. The structure of the

Card Specific Data (CSD) register is compliant with CSD Structure 1.0.

1.5.9.2. Negotiating Operation Conditions

The miniSD Card supports the operation condition verification sequence defined in the miniSD Card standard

specifications. Should the miniSD Card host define an operating voltage range, which is not supported by the

miniSD Card it will put itself in an inactive state and ignore any bus communication. The only way to get the card

out of the inactive state is by powering it down and up again.

In Addition the host can explicitly send the card to the inactive state by using the GO_INACTIVE_STATE

command.

1.5.9.3. Card Acquisition and Identification

The miniSD bus is a single master (miniSD host application) and multi-slaves (cards) bus. The Clock and Power

lines are common to all cards on the bus. During the identification process, the host accesses each card separately

through its own command lines. The miniSD’s CID register is pre-programmed with a unique card identification

number, which is used during the identification procedure.

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SanDisk SD032 Handbuch Seite 11