
Agere Systems Inc.
141
Data Sheet
July 2001
T8302 Internet Protocol Telephone
Advanced RISC Machine (
ARM
)
11 10/100 2-Port Repeater and Backplane Segment Controller
(continued)
11.5.8 Global Port Status Register, for Port 0, 1
The
global port status register
contains the status of the repeater slice. The register is read-only. Writes will not
alter the contents of this register. All status bits are valid with
RCVE
= 0 or 1
(see Table 117 on page 136)
.
Table 121. Global Port Status Register, for Port 0, 1
Address—Port 0 (0xE001 2030), Port 1 (0xE001 2230)
6
5
MIS_ERR
LIS
ISO
State on RST
(0)
Reserved. These bits are reserved and will return 0s on being read.
(0)
Data rate mismatch.
This bit is set when a data FIFO overrun or underrun
has occurred. Once set, the user must read this register to clear this bit.
(0)
Link integrity status.
This bit indicates the status of the link as derived from
the LIS inputs from the PHY.
Bit #
Name
Bit #
31:8
7
31:8
RSVD
Name
RSVD
MIS_ERR
7
4
3
2
1
0
SM
DS
VLE
CAR
PART
Description
6
LIS
A 1 indicates
LINK_STATUS
= OK.
A 0 indicates
LINK_STATUS
= FAIL.
Isolated. This bit indicates whether or not the port has been isolated by
the carrier integrity monitor state machine due to excessive false carriers
detected.
5
ISO
(0)
A 1 indicates that the port has been isolated.
A 0 indicates a nonisolated condition.
Speed mismatch. This bit indicates whether or not the frequency of the
RX_CLK
clock is correct for the selected speed.
4
SM
(1)
A 1 indicates the incorrect frequency.
A 0 indicates a correct frequency.
Internal circuitry compares the receive clock frequency to the
GSPS
pin
frequency selection to determine a match or mismatch condition. This bit
is valid even when the port is disabled.
Detected speed. This bit indicates the frequency of the received clock
(
RX_CLK
) on the port and therefore, the speed of the received data
stream. Under normal conditions, the following is true.
3
DS
(1)
A 1 indicates a frequency of 10 MHz or 10 Mbits/s.
A 0 indicates 25 MHz or 100 Mbits/s.
Very long event.
2
VLE
(0)
In 10 Mbits/s mode, it indicates
MJLP
has expired.
In 100 Mbits/s mode, a 1 indicates the port is in receive jabber due to an
excessively long
CRS
currently being applied.
Carrier status. Indicates
CRS
is asserted at time of polling this bit. This bit
is not latched.
Autopartition status. A 1 indicates the repeater port is currently parti-
tioned.
1
CAR
(0)
0
PART
(0)