xr
XRT83SL28
REV. 1.0.0
8-CHANNEL E1 SHORT-HAUL LINE INTERFACE UNIT
TABLE 10: MICROPROCESSOR REGISTER BIT DESCRIPTION
CHANNEL CONTROL REGISTER (0X04H, 0X08H, 0X0CH, 0X10H, 0X14H, 0X18H, 0X1CH, 0X20H)
Register
Default
Value
Type
R/W
BIT
NAME
FUNCTION
(HW reset)
D5
ARAOS_n Automatic Receive All Ones
If ARAOS_n is selected, an all ones pattern will be sent to the
0
RPOS/RNEG outputs if the channel experiences an RLOS condi-
tion. If RLOS does not occur, ARAOS_n will remain inactive.
"0" = Disabled
"1" = Enabled
D4
D3
D2
ATAOS_n Automatic Transmit All Ones
R/W
R/W
R/W
0
0
0
If ATAOS_n is selected, an all ones pattern will be transmitted from
TTIP/TRING if the channel experiences an RLOS condition. If
RLOS does not occur, ATAOS_n will remain inactive.
"0" = Disabled
"1" = Enabled
TAOS_n Transmit All Ones
If TAOS_n is selected, an all ones pattern will be transmitted from
TTIP/TRING if the transmitter is turned on. Remote Loop Back
has priority over TAOS.
"0" = Disabled
"1" = Enabled
TXOE_n Transmit Output Enable
Upon power up, the tranmitters are tri-stated. This bit is used to
enable the transmitter for this channel if the TxOE pin is pulled
"High". If the TxOE pin is pulled "Low", all 8 transmitters are tri-
stated.
"0" = Transmitter is disabled
"1" = Transmitter is enabled if TxOE pin is pulled "High"
D1
D0
TERSEL1 Receive Line Impedance Select
R/W
0
0
TERSEL0 TERSEL[1:0] are used to select the internal line impedance.
"00" = 75Ω for Tx and "High-Z" for Rx
"01" = 120Ω for Tx and "High-Z" for Rx
"10" = 75Ω for Tx and Rx
"11" = 120Ω for Tx and Rx
37
EXAR [ EXAR CORPORATION ]
