3X38FTR Datasheet, PDF (55/64 Pages) Agere Systems – OCTAL-FET (Fast Ethernet Transceiver) for 10Base-T/100Base-TX/FX

Preliminary Data Sheet
September 2000
3X38FTR 208-Pin SQFP
OCTAL-FET for 10Base-T/100Base-TX/FX
Register Information (continued)
Table 35. MR31—Device-Specific Register 4 (Quick Status) Bit Descriptions
Register/Bit*
Type^†
Description
31.15 (ERROR)
R Receiver Error. When this bit is a 1, it indicates that a receive error has been
detected. This bit is valid in 100 Mbits/s only. This bit will remain set until cleared by
reading the register. Default is a 0.
31.14 (RXERR_ST)/ R False Carrier. When bit [31.7] is set to 0 and this bit is a 1, it indicates that the carrier
(LINK_STAT_CHANGE)
detect state machine has found a false carrier. This bit is valid in 100 Mbits/s only. This
bit will remain set until cleared by reading the register. Default is 0.
Link Status Change. When bit [31.7] is set to a 1, this bit is redefined to become the
LINK_STAT_CHANGE bit and goes high whenever there is a change in link status (bit
[31.11] changes state).
31.13 (REM_FLT)
31.12 (UNLOCKED)/
(JABBER)
R Remote Fault. When this bit is a 1, it indicates a remote fault has been detected. This
bit will remain set until cleared by reading the register. Default is a 0.
R Unlocked/Jabber. If this bit is set when operating in 100 Mbits/s mode, it indicates
that the TX descrambler has lost lock. If this bit is set when operating in 10 Mbits/s
mode, it indicates a jabber condition has been detected. This bit will remain set until
cleared by reading the register.
31.11 (LSTAT_OK)
31.10 (PAUSE)
R Link Status. When this bit is a 1, it indicates a valid link has been established. This bit
has a latching low function: a link failure will cause the bit to clear and stay cleared
until it has been read via the management interface.
R Link Partner Pause. When this bit is set to a 1, it indicates that the 3X38 wishes to
exchange flow control information.
31.9 (SPEED100)
31.8 (FULL_DUP)
R Link Speed. When this bit is set to a 1, it indicates that the link has negotiated to
100 Mbits/s. When this bit is a 0, it indicates that the link is operating at 10 Mbits/s.
R Duplex Mode. When this bit is set to a 1, it indicates that the link has negotiated to
full-duplex mode. When this bit is a 0, it indicates that the link has negotiated to half-
duplex mode.
31.7 (INT_CONF)
31.6 (INT_MASK)
R/W Interrupt Configuration. When this bit is set to a 0, it defines bit [31.14] to be the
RXERR_ST bit and the interrupt pin (MASK_STAT_INT) (pin 69) goes low whenever
any of bits [31.15:12] go high, or bit [31.11] goes low. When this bit is set high, it rede-
fines bit [31.14] to become the LINK_STAT_CHANGE bit, and the interrupt pin
(MASK_STAT_INT) goes low only when the link status changes (bit [31.14] goes
high). This bit defaults to 0.
R/W Interrupt Mask. When set high, no interrupt is generated by this channel under any
condition. When set low, interrupts are generated according to bit [31.7].
31.5:3
(LOW_AUTO_STATE)
R Lowest Autonegotiation State. These 3 bits report the state of the lowest autonego-
tiation state reached since the last register read, in the priority order defined below:
31.2:0
(HI_AUTO_STATE)
000: Autonegotiation enable.
001: Transmit disable or ability detect.
010: Link status check.
011: Acknowledge detect.
100: Complete acknowledge.
101: FLP link good check.
110: Next page wait.
111: FLP link good.
R Highest Autonegotiation State. These 3 bits report the state of the highest autone-
gotiation state reached since the last register read, as defined above for bit [31.5:3].
* The format for the bit descriptions is as follows: the first number is the register number, the second number is the bit position in the register.
† R = read, W = write.
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