User's Manual

Interface

5.4 Command Protocol

The host should confirm that the BSY bit of the Shadow Block Status register of

the device is 0 prior to issue a command. If BSY bit is 1, the host should wait for

issuing a command until BSY bit is cleared to 0.

Commands can be executed only when the DRDY bit of the Status register is 1.

However, the following commands can be executed even if DRDY bit is 0.

• EXECUTE DEVICE DIAGNOSTIC

• INITIALIZE DEVICE PARAMETERS

Note: Each FIS type is referred to as follows in this section.

FIS (Frame Information Structure) type Abbreviation

DMA Active - Device to Host DMA Active

DMA Setup - Device to Host or Host to Device

(Bidirectional)

DMA Setup

Set Device Bits - Device to Host SetDB

BIST Active - Bidirectional BIST Active

PIO Setup - Device to Host PIO Setup

Data - Host to Device or Device to Host (Bidirectional) DATA

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