Medium Access Control (MAC) and Physical Layer (PHY) - CISE

4-June-07 P1901_PRO_016_r0
4.2.2.2 TDR side
From a slave standpoint, a TDR can be in two different states: Registered or Unregistered (see Figure 27).
� Unregistered: This is the initial state of a slave. An unregistered slave is only authorized to answer access
frames as required by the access protocol. When the access protocol process is completed and successful,
the slave enters the Registered state.
� Registered: The following specific requirements apply to this state:
o A Registered TDR shall never reply to access frames from its current master. It might reply to
access frames from another master if it wishes to change its current master.
o A Registered TDR, at the reception of a TDR Polling Frame, shall ensure to transmit Access
Frames, Polling Frames and TDR Polling Frames for all its slaves in the maximum specified
intervals (see 4.6). Afterwards, the TDR shall reply to the TDR Polling Frame sent by the
master indicating whether it wants to be Active or it wants to stay Idle but still Registered.
o An Registered TDR, in Idle state, shall not transmit any Data Token. It shall no transmit any
data either, except for service class 7 traffic. Nevertheless, the TDR could transmit data in the
TDR Polling Reply Frame when it indicates that it wants to be Active again, if it has enough
remaining validity for it.
o A Registered TDR which has not received any TDR Polling Token or Data Token for more
than MAX_ALIVE_TOKENS*MAX_ACTIVE POLL_INTERVAL shall enter the Unregistered state.
The counting of this time interval shall be initialized at the end of the TDR Polling Reply
symbol sent or at the reception of the last Data Token received by the Registered slave,
whichever is later.
Submission page 89 UPA-OPERA