User Manual

Introduction to the TriFlash with SD Interface

1-5

1.5.5. Using the Erase Command

The Erase command provides the capability to substantially increase the write performance of the TriFlash. 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.

1.5.6. Automatic Sleep Mode

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

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

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

the TriFlash is in sleep mode except when the host is accessing it, thus conserving power.

When the host is ready to access the TriFlash and it is in sleep mode, any command issued to the TriFlash will cause

it to exit sleep and respond.

1.5.7. TriFlash—SD Bus Mode

The following sections provide valuable information for TriFlash in SD Bus Mode.

1.5.7.1. TriFlash Standard Compliance

The TriFlash is fully compliant with the SD Memory Card Physical Layer Standard Specification V1.01. The

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

1.5.7.2. Negotiating Operation Conditions

The TriFlash supports the operation condition verification sequence defined in the SD Memory Card Standard

Specifications. Should the TriFlash host define an operating voltage range, which is not supported by the TriFlash,

it will put itself in an inactive state and ignore any bus communication. The only way to get the TriFlash out of the

inactive state is by powering it down and up again.

In addition, the host can explicitly send the TriFlash to the inactive state by using the GO_INACTIVE_STATE

command.

1.5.7.3. Device Acquisition and Identification

The SD bus is a single master (TriFlash host application) and multi-slaves (devices) bus. The Clock and Power lines

are common to all devices on the bus. During the identification process, the host accesses each device separately

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

identification number, which is used during the identification procedure.