Fujitsu MAU3036RC SERIES, Technical Manual

Page: 79 / 392

1.5 Address frames
C141-C009 1-57
b) DONE (CREDIT TIMEOUT) specifies that the transmitter still has SSP
frames to transmit but did not receive an RRDY granting frame credit within
1 ms, or the transmitter has received a CREDIT_BLOCKED and has
consumed all RRDYs received; and
c) DONE (ACK/NAK TIMEOUT) specifies that the transmitter transmitted an
SSP frame but did not receive the corresponding ACK or NAK within 1 ms.
As a result, the ACK/NAK count is not balanced and the transmitter is going
to transmit a BREAK in 1 ms unless the recipient replies with DONE and the
connection is closed.
If the transmitter has no more SSP frames to transmit and receives a
CREDIT_BLOCKED, it may transmit either DONE (NORMAL) or DONE
(CREDIT TIMEOUT).
After transmitting DONE, the transmitting phy initializes and starts a 1 ms DONE
Timeout timer.
After transmitting DONE, the transmitting phy shall not transmit any more SSP
frames during this connection. However, the phy may transmit ACK, NAK,
RRDY, and CREDIT_BLOCKED as needed after transmitting DONE if the other
phy is still transmitting SSP frames in the reverse direction. Once an SSP phy has
both transmitted and received DONE, it shall close the connection by transmitting
CLOSE (NORMAL).
Figure 1.20 shows the sequence for a closing an SSP connection.
DONE
CLOSE primitive
sequence
DONE
CLOSE primitive
sequence
time time
transmitter receiver
(ACK, NAK, RRDY, and
CREDIT_BLOCKED may be
sent after the first DONE)
Figure 1.20 Closing an SSP connection example