TAN-042
Designing the XRT71D00 and the XRT73L00 Devices to
operate in the Host Mode, and to be accessed via a single Chip
Select pin.
Preliminary
July 19, 2001
Revision 1.03
37
Command Register CR4
Bit D0 – RLB (Loop-back Select)
This “Read/Write” bit-field, along with “D1” (LLB) permits the user to configure the
XRT73L00 device to operate in either the “Analog-Local”, “Digital-Local” or “Remote”
Loop-back Modes.
The following table presents the relationship between the states of these two bit-fields
and the corresponding loop-back mode of the XRT73L00 device.
Table A1, The Relationship between the states of bits D0 (RLB), D1 (LLB) and the
corresponding Loop-back Modes of the XRT73L00 Device
D0 (RLB)
D1 (LLB)
Resulting Loop-back Mode
0
0
No Loop-back Mode (Normal Operation)
0
1
Analog Local Loop-back Mode
1
0
Remote Loop-back Mode
1
1
Digital Local Loop-back Mode
Bit D1 – LLB (Loop-back Select)
This “Read/Write” bit-field, along with “D0” (RLB) permits the user to configure the
XRT73L00 device to operate in either the “Analog-Local”, “Digital-Local” or “Remote”
Loop-back Modes.
The following table presents the relationship between the states of these two bit-fields
and the corresponding loop-back mode of the XRT73L00 device.
Table A2, The Relationship between the states of bits D0 (RLB), D1 (LLB) and the
corresponding Loop-back Modes of the XRT73L00 Device
D0 (RLB)
D1 (LLB)
Resulting Loop-back Mode
0
0
No Loop-back Mode (Normal Operation)
0
1
Analog Local Loop-back Mode
1
0
Remote Loop-back Mode
1
1
Digital Local Loop-back Mode
Bit D2 – E3 (E3 Mode Select)
This “Read/Write” bit-field, along with bit D3 (STS-1/DS3*) permits the user to
configure the XRT73L00 device to operate in either the DS3, E3 or STS-1 Mode.