Package dependent segment terminal remapping for driving liquid crystal displays
A microcontroller for controlling a liquid crystal display (LCD) is mountable in any one of multiple package types. The microcontroller includes a LCD controller to generate logical mapping signals indicative of voltages to be applied to segment terminals of a LCD glass. A driver circuit drives the segment terminals selectively. A remapping unit receives the logical mapping signals from the LCD controller and maps the logical mapping signals, for each of the package types, to physical segment terminal drivers in the driver circuit based on a distribution of I/O terminals that are bonded for each package type when that package type is used with the LCD glass.
1. A microcontroller for controlling a LCD, the microcontroller being mountable in any one of a plurality of package types, the microcontroller comprising:
a LCD controller to generate logical mapping signals that indirectly code for voltages to be applied to electrodes of a LCD glass;
a driver circuit to drive the electrodes;
a remapping unit to receive the logical mapping signals from the LCD controller, wherein, in addition to an input to receive the logical mapping signals from the LCD controller, the remapping unit has inputs to receive, respectively (i) a package identifier indicative of the specified one of the package types, (ii) an indication of the number of LCD segment terminals to be used, and (iii) a vector describing which segment terminals are used for the particular package type,
wherein the remapping unit is operable to map the logical mapping signals to the driver circuit, based on information received at each of the inputs, by converting, the logical mapping signals to enable signals and to physical segment data to be provided to the driver circuit.
2. The microcontroller of claim 1 wherein the remapping unit maps the logical mapping signals to the driver circuit based, at least in part, on a distribution of I/O pads that are bonded for the particular package type when used with the LCD glass.
3. The microcontroller of claim 1 including:
circuitry storing a first vector indicative of which LCD segment terminals are bonded for the particular package type,
wherein the remapping unit includes a logical-to-physical data mapping unit that maps the logical mapping signals to physical segment terminal drivers in the driver circuit based on the first vector.
4. The microcontroller of claim 3 wherein the logical-to-physical data mapping unit is arranged to convert the first vector to a second vector, wherein each bit position in the second vector specifies a corresponding physical segment terminal identifier, and wherein the logical-to-physical data mapping unit is arranged to remap the logical mapping signals based, at least in part, on the second vector.
5. The microcontroller of claim 4 wherein each bit in the second vector depends on the number of previous bits in the first vector having a value that indicates a corresponding LCD segment terminal is bonded for the particular package type.
6. The microcontroller of claim 5 wherein the logical-to-physical data mapping unit includes a plurality of pairs of selectors, wherein a first selector in each pair allows one of the logical mapping signals to pass to its respective output based on a corresponding bit in the second vector.
7. The microcontroller of claim 3 wherein the remapping unit includes a look-up table that generates output to enable driving selected ones of the LCD segment terminals based on the particular package type and based on the number of LCD segment terminals programmed for use.
8. The microcontroller of claim 7 wherein the look-up table stores a plurality of rows of information each of which is based on the first vector and reflects a different number of the LCD segment terminals programmed for use.
9. The microcontroller of claim 7 wherein the remapping unit further includes a plurality of look-up tables that generate output to enable driving selected ones of the LCD segment terminals based on the particular package type and based on the number of LCD segment terminals programmed for use.
10. The microcontroller of claim 9 wherein the remapping unit includes:
a first selector to select output from a particular one of the logical-to-physical data mapping units based on an identifier for the package type;
a second selector to select output from a particular one of the look-up tables based on the identifier for the package type; and
a third selector to select a particular subset of the output from the particular look-up table based on the number of LCD segment terminals programmed for use.
11. The microcontroller of claim 3 wherein the circuitry storing the first vector indicative of which LCD segment terminals are bonded for the particular package type comprises combinatorial logic.
12. The microcontroller of claim 1 including:
circuitry storing first vectors each of which describes which LCD segment terminals are bonded for a respective particular package type,
wherein the remapping unit includes a plurality of logical-to-physical data mapping units each of which maps the logical mapping signals to physical segment terminal drivers in the driver circuit based on a respective one of the first vectors.
13. A method of driving LCD segment terminals, the method comprising:
receiving, in a remapping unit, (i) logical mapping signals from a LCD controller, wherein the logical mapping signals indirectly code for voltages to be applied to segment terminals of a LCD glass, (ii) a package identifier indicative of a specified package type, (iii) an indication of the number of LCD segment terminals to be used, and (iv) a vector describing which segment terminals are used for the particular package type;
mapping the logical mapping signals to physical segment terminal drivers based on the information received in the remapping unit; and
applying voltages to the segment terminals in accordance with the mapping.
14. The method of claim 13 including mapping the logical mapping signals to the physical segment terminal drivers based, at least in part, on a distribution of I/O pads that are bonded for the particular package type when used with the LCD glass.
15. The method of claim 13 including:
storing a first vector indicative of which LCD segment terminals are bonded for the particular package type,
and mapping the logical mapping signals to the physical segment terminal drivers based on the first vector.
16. The method of claim 15 wherein mapping the logical mapping signals to the physical segment terminal drivers based on the first vector includes:
converting the first vector to a second vector, wherein each bit position in the second vector specifies a corresponding physical segment terminal identifier; and
remapping the logical mapping signals based, at least in part, on the second vector.
17. The method of claim 16 wherein each bit in the second vector depends on the number of previous bits in the first vector having a value that indicates a corresponding LCD segment terminal is bonded for the particular package type.
18. The method of claim 17 including selecting a particular one of the logical mapping signals as an output based on a corresponding bit in the second vector if a corresponding bit in the first vector has a value indicating that the corresponding LCD segment terminal is bonded for the particular package type.
19. The method of claim 15 including generating output to enable driving selected ones of the LCD segment terminals based on the particular package type and based on the number of LCD segment terminals programmed for use.
20. A microcontroller for controlling a LCD, the microcontroller being mountable in any one of a plurality of package types, the microcontroller comprising:
a LCD controller to generate logical mapping signals indicative of voltages to be applied to segment terminals of a LCD glass;
a driver circuit to drive the segment terminals selectively;
a remapping unit to receive the logical mapping signals from the LCD controller and to map the logical mapping signals, for each of the package types, to physical segment terminal drivers in the driver circuit based on a distribution of I/O terminals that are bonded for each package type when that package type is used with the LCD glass,
wherein, in addition to an input to receive the logical mapping signals from the LCD controller, the remapping unit has inputs to receive, respectively (i) a package identifier indicative of the specified one of the package types, (ii) an indication of the number of LCD segment terminals to be used, and (iii) a vector describing which segment terminals are used for the particular package type.
21. The microcontroller of claim 20 including:
circuitry storing information representing first vectors each of which indicates which LCD segment terminals are bonded for a respective one of the package types,
wherein the remapping unit includes a plurality of logical-to-physical data mapping units each of which maps the logical mapping signals to the physical segment terminal drivers based on a respective one of the first vectors.
22. The microcontroller of claim 21 wherein the remapping unit further includes a plurality of look-up tables, each of which generates output to enable driving selected ones of the segment terminals based on the particular package type and based on the number of LCD segment terminals programmed for use.
23. The microcontroller of claim 22 wherein the remapping unit further includes:
a first selector to select output from a particular one of the logical-to-physical data mapping units based on an identifier for the package type;
a second selector to select output from a particular one of the look-up tables based on the identifier for the package type; and
a third selector to select a particular subset of the output from the particular look-up table based on the number of LCD segment terminals programmed for use.