Advanced cable detection
Publication Date: 2013-Jun-26
The IP.com Prior Art Database
Disclosed is a methodology for Multiple cable detection by single wires.
Page 01 of 4
Advanced cable detection Problem statement:
- Current cable presence detection : Using a GPIOs of chipset and connect to target connector. Single GPIO can only monitor single cable presence.
- Chipset detect high or low level (1 or 0) of this signal and tell if cable present or not.
If cable attach onto connector, presence detect signal will be pull UP to native voltage of cable. (High level on signal). Chipset will know cable plug-in happen.
If cable Didn't attach onto connector, presence detect signal will be pull DOWN by external resistor (Low level on signal). Chipset will know cable NO plug-in happen.
Disadvantage for current design:
- If numerous cable-presence need to be detected, they will occupied plenty of GPIOs count of chipset. Limit chipset bandwidth.
- Numerous cable-presence signal routing will occupy more space and enlarge layout constraint.
- When GPIOs number is not enough, I/O expander need to be used for detection. Which means most cost.
Summary of solution:
- Using this technique to implement Multi-cable presence detect are with following advantage:
1. Save PCB space and make signal routing smoothly.
2. Minimize GPIO count to make Chipset capability more flexible. Signal routing space can be conserved:
Page 02 of 4
Page 03 of 4
Vin= P3V3 x (Rx)/(R4+Rx), Rx=shunt resistance for R1, R2, R3
Detail of solution:
- Using single ADC (analog-digital converter) capable signal can replace numerous GPIOs.
- In theory, this d...