Command Protocol - Fujitsu MHW2120BK Maintenance 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.
Register - Host to Device
Register - Device to Host
DMA Active - Device to Host
DMA Setup - Device to Host or Host to Device
(Bidirectional)
Set Device Bits - Device to Host
BIST Active - Bidirectional
PIO Setup - Device to Host
Data - Host to Device or Device to Host (Bidirectional)
5-174
FIS (Frame Information Structure) type Abbreviation
RegHD
RegDH
DMA Active
DMA Setup
SetDB
BIST Active
PIO Setup
DATA
C141-E261