CONT

T,R

Consider the immediately previous primitive to be repeating until the next primitive is received. Ignore following non-primitive characters.

DMAT

R

Terminate a transfer in progress. This primitive is defined in the protocol, but the ATA command protocol does not tolerate its use and it should therefore not be used.

SYNC

T,R

Interface idle

X_RDY

T

Request transmission of a frame of layload data. Signals readiness to transmit. (transmitter ready)

R_RDY

R

In response to an X_RDY, signal that the interface is ready to start reception of payload data. (receiver ready)

SOF

T

Marks the start of a frame of payload data

R_IP

R

Used as backchannel idle primitive during payload data reception. (reception in progress).

EOF

T

Marks the end of a frame or data payload. The previous payload character was the CRC.

WTRM

T

Awaiting an R_OK or R_ERR signal from the receiver.

R_ERR

R

Signal the transmitter that an error was detected in the received payload data. (received error)

R_OK

R

Signal the transmitter that no error was detected in the received payload data. (received OK)

HOLD

T,R

Transmitted over the backchannel when the receiver wants to signal the transmitter to hold off on transmitting payload data. Transmitted in place of data when the transmitter does not have payload data ready to be delivered.

HOLDA

T,R

Transmitted in response to a received HOLD primitive to acknowledge that transmitted data is no longer flowing.

PMREQ_P