Datasheet

XIO2213B
SCPS210F –OCTOBER 2008–REVISED MAY 2013 www.ti.com
Table 10-4. Page 0 (Port Status) Register Field Description
FIELD SIZE TYPE DESCRIPTION
Astat 2 Rd TPA line state. This field indicates the instantaneous TPA line state of the selected port,
encoded as:
Code Arbitration Value
11 Z
10 1
01 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 necessarily mean that the port is active. For IEEE Std 1394b-2002-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 IEEE Std 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 RdWr Port disabled control. If this bit is 1, 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 1 Rd Negotiated speed. Indicates the maximum speed negotiated between this port and its
immediately connected port. The encoding is as for Max_port_speed. It is set on connection
when in beta mode, or to a value established during self-ID when in IEEE Std 1394a-2000
mode.
PIE 1 RdWr 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 Standby fault. 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, the data sent during packet transmission is not
scrambled.
B_Only 1 Rd Beta-mode operation only. For the XIO2213B, this bit is set to 0 for all ports.
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 an
IEEE Std 1394a-2000-style connect-detect circuit.
184 Physical Layer (PHY) Section Copyright © 2008–2013, Texas Instruments Incorporated
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