N-wire two-level digital interface
A receiver for an N-wire digital interface, where N is any integer exceeding two, has N input terminals, a common node and N detection stages. Each of the N detection stages has a resistive element coupled between the common node and a respective one of the N input terminals, and a comparator having a first input coupled to the respective one of the N input terminals and a second input coupled to the common node.
1. A receiver comprising:
N input terminals, where N is any integer exceeding two;
a common node; and
N detection stages, each of the N detection stages including:
a resistive element, each of the resistive elements coupled between the common node and a respective one of the N input terminals; and
a comparator, each of the comparators having a first input coupled directly to a respective one of the N input terminals and a second input coupled directly to the common node, wherein the resistive element of each of the N detection stages has a same resistance value.
2. The receiver as claimed in claim 1 , further comprising:
a decoder coupled to comparator outputs of the N detection stages and configured to determine a received symbol dependent on states of the comparator outputs.
3. The receiver as claimed in claim 2 , wherein the decoder comprises a first look-up table for mapping the states of the comparator outputs to the received symbol.
4. The receiver as claimed in claim 1 , wherein N is one of: three, four and five.
5. A signaling system comprising:
a transmitter configured to generate N signaling voltages applied to wires of an N-wire interface, respectively, each of the N signaling voltages being indicative of a different one of N bits to be transmitted, and having a value selected from two values; and
a receiver having N input terminals, a common node, and N detection stages, where N is any integer exceeding two, each of the N detection stages including:
a resistive element, each of the resistive elements coupled between the common node and a respective one of the N input terminals; and
a comparator, each of the comparators having a first input coupled directly to a respective one of the N input terminals and a second input coupled directly to the common node,
wherein the resistive element of each of the N detection stages has a same resistance value, and the N input terminals are coupled to the wires of the N-wire interface, respectively.
6. The signaling system as claimed in claim 5 , further comprising an encoder configured to map a symbol to the N bits to be transmitted.
7. The signaling system as claimed in claim 6 , wherein the encoder comprises a second look-up table for mapping the symbol to the N bits to be transmitted.
8. The signaling system as claimed in claim 5 , wherein N is three, and wherein two of the N signaling voltages have a first value and a third one of the N signaling voltages has a second value, which is different from the first value.
9. The signaling system as claimed in claim 5 , wherein N is four, and wherein at least two of the N signaling voltages have a first value and the at least one other of the N signaling voltages has a second value, which is different from the first value.
10. The signaling system as claimed in claim 5 , wherein N is five, and wherein three of the N signaling voltages have a first value and two of the N signaling voltages have a second value, which is different from the first value.
11. A method of operating a signaling system, the method comprising:
providing a receiver having N input terminals, a common node, and N detection stages, where N is any integer exceeding two, each of the N detection stages including:
a resistive element, each of the resistive elements coupled between the common node and a respective one of the N input terminals; and
a comparator, each of the comparators having a first input coupled directly to a respective one of the N input terminals and a second input coupled directly to the common node, wherein the resistive element of each of the N detection stages has a same resistance value;
selecting N signaling voltages, wherein each of the N signaling voltages is selected from two values;
delivering the N signaling voltages to the N input terminals of the receiver, respectively; and
determining a received symbol dependent on the N signaling voltages.
12. The method as claimed in claim 11 , wherein N is three, and wherein two of the N signaling voltages have a first value and a third one of the N signaling voltages has a second value, which is different from the first value.
13. The method as claimed in claim 11 , wherein N is four, wherein at least two of the N signaling voltages have a first value and at least one other of the N signaling voltages has a second value, which is different from the first value.
14. The method as claimed in claim 11 , wherein N is five, and wherein three of the N signaling voltages have a first value and two of the N signaling voltages have a second, which is value different from the first value.
15. A wireless communication device comprising:
a transmitter configured to generate N signaling voltages applied to wires of an N-wire interface, respectively, each of the N signaling voltages being indicative of a different one of N bits to be transmitted, and having a value selected from two values; and
a receiver having N input terminals, a common node, and N detection stages, where N is any integer exceeding two, each of the N detection stages including:
a resistive element, each of the resistive elements coupled between the common node and a respective one of the N input terminals; and
a comparator, each of the comparators having a first input coupled directly to a respective one of the N input terminals and a second input coupled directly to the common node,
wherein the resistive element of each of the N detection stages has a same resistance value, and the N input terminals are coupled to the wires of the N-wire interface, respectively.