5.4 Command Protocol
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 |
|
|
Register - Host to Device | RegHD |
Register - Device to Host | RegDH |
DMA Active - Device to Host | DMA Active |
DMA Setup - Device to Host or Host to Device | DMA Setup |
(Bidirectional) |
|
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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