42.6.1.6 LCD Pins Selection
Selection of maximum 48 segment/common lines from 52 LCD pins
There are 52 LCD pins (LPx), of which up to 48 LCD pins can be enabled or disabled individually according to the LCD glass. Each LCD pin can be configured as frontplane (SEG) or backplane (COM), offering various configurations. The maximum number of SEG lines and COM lines are defined in the table below.
| Duty | #COM Lines | Max #SEG Lines |
|---|---|---|
| Static | 1 | 44 |
| 1/2 | 2 | 44 |
| 1/3 | 3 | 44 |
| 1/4 | 4 | 44 |
| 1/6 | 6 | 42 |
| 1/8 | 8 | 40 |
- For LP[31:0], write to LCD Pin Enable Low register bits LPENL[31:0]
- For LP[51:32], writ to LCD Pin Enable High register bits LPENH[18:0]
Writing a '0' to a bit in LPENL or LPENH will disable the corresponding LCD pin. The number of LCD pins enabled should not be higher than the maximum of COM and SEG lines supported (see the table above). Any LCD pin can be enabled individually, LCD pins do not have to be enabled in contiguous manner.
A disabled LCD pin can thus be used as GPIO or alternate function.
According to their duty configuration, COM lines are assigned first to LCD pins enabled. The number of SEG lines enabled is thus the number of LCD pins enabled minus the number of COM lines assigned (limited to the maximum SEG lines supported according duty selection). COM and SEG lines are always assigned in ascending order, as shown in the figure here.
