Datasheet
TSB41BA3D
SLLS959A – DECEMBER 2008 – REVISED MARCH 2009 ...............................................................................................................................................
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Table 7. Page 0 (Port Status) Register Field Descriptions
FIELD SIZE TYPE DESCRIPTION
Astat 2 Rd TPA line state. This field indicates the instantaneous TPA line state of the selected port,
encoded as follows:
Code Arb Value
11 Z
01 1
10 0
00 invalid
Bstat 2 Rd TPB line state. This field indicates the TPB line state of the selected port. This field has the
same encoding as the Astat field.
Ch 1 Rd Child/parent status. A 1 indicates that the selected port is a child port. A 0 indicates that the
selected port is the parent port. A disconnected, disabled, or suspended port is reported as a
child port. The Ch bit is invalid after a bus reset until tree-ID has completed.
Con 1 Rd
Debounced port connection status. This bit indicates that the selected port is connected. The
connection must be stable for the debounce time of approximately 341 ms for the Con bit to
be set to 1. The Con bit is reset to 0 by hardware reset and is unaffected by bus reset.
NOTE: The Con bit indicates that the port is physically connected to a peer PHY, but this
does not mean that the port is necessarily active. For 1394b-coupled connections, the Con bit
is set when a port detects connection tones from the peer PHY and operating-speed
negotiation is completed.
RxOK 1 Rd Receive OK. In 1394a-2000 mode this bit indicates the reception of a debounced TPBias
signal. In Beta mode, this bit indicates the reception of a continuous electrically valid signal.
NOTE: RxOK is set to false during the time that only connection tones are detected in Beta
mode.
Dis 1 Rd/Wr Port disabled control. If this bit is 1, then the selected port is disabled. The Dis bit is reset to 0
by hardware reset (all ports are enabled for normal operation following hardware reset). The
Dis bit is not affected by bus reset. When this bit is set, the port cannot become active;
however, the port still tones, but does not establish an active connection.
Negotiated_speed 3 Rd Indicates the maximum speed negotiated between this PHY port and its immediately
connected port. The encoding is as for Max_port_speed. It is set during connection when in
Beta mode or to a value established during self-ID when in 1394a-2000 mode.
PIE 1 Rd/Wr Port-event-interrupt enable. When this bit is 1, a port event on the selected port sets the
port-event-interrupt (PEI) bit and notifies the link. This bit is reset to 0 by a hardware reset
and is unaffected by bus reset.
Fault 1 Rd/Wr Fault. This bit indicates that a resume fault or suspend fault has occurred on the selected
port, and that the port is in the suspended state. A resume-fault occurs when a resuming port
fails to detect incoming cable bias from its attached peer. A suspend fault occurs when a
suspending port continues to detect incoming cable bias from its attached peer. Writing 1 to
this bit clears the Fault bit to 0. This bit is reset to 0 by hardware reset and is unaffected by
bus reset.
Standby_fault 1 Rd/Wr This bit is set to 1 if an error is detected during a standby operation and cleared on exit from
the standby state. A write of 1 to this bit or receipt of the appropriate remote command packet
clears it to 0. When this bit is cleared, standby errors are cleared.
Disscrm 1 Rd/Wr Disable scrambler. If this bit is set to 1, then the data sent during packet transmission is not
scrambled.
B_Only 1 Rd Beta-mode operation only. For the TSB41BA3D, this bit is set to 0 for all ports when all ports
are programmed as bilingual or a combination of bilingual and data-strobe (1394a) only. If a
port has been programmed to be Beta-only at a selected speed (for example B1 is Beta-only
S100), then this bit is set to 1.
DC_connected 1 Rd If this bit is set to 1, the port has detected a dc connection to the peer port by means of a
1394a-style connect-detect circuit.
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