Simulates a dot matrix LCD display, using curses (a cursor control library) to manage the graphics inside a text window.
The LCD display model is somewhat abstracted from the physical device:
A real display typically has separate row and column pins that are cycled to select each pixel in the display. These are replaced by 2 pins in the model. The FR (frame) pin is driven to 1 to identify that a new frame is starting, and driven to 0 when the frame is finished. The row-col pin incorporates all the functionality of the row and column drivers on the real chip. This pin is driven once for each "on" pixel in the display, and the value on the pin is the [X,Y] co-ordinates of the pixel, encoded as two adjacent 16-bit values in the 32-bit pin value.
With these two pins, a display refresh cycle starts when the FR pin is asserted; the [X,Y] co-ordinates of all the "on" pixels are then transmitted on the row-col pin; and the FR pin is de-asserted to end the refresh cycle.
The physical device must be refreshed periodically, but the model retains its last written values indefinitely.
| Behaviors | |
|---|---|
| configuration |
The width and height attributes set the display size in units of characters. For example, the default values are 80 and 24 for width and height, respectively. This is the size of a standard CRT window. |
| display |
See discussion of the FR and row-col pins in Modeling section above. |
| SID Conventions | ||
|---|---|---|
| functional component | supported | This is a functional component. |
| Save/restore | supported | Save/restore is supported. |
| Triggerpoint | supported | Triggerpoint support is available on all three input pins. |
Related components
The LCD display is typically connected to an LCD controller. The following configuration file segment shows how the hw-lcd-hd44780u LCD controller can be connected to the display:
new hw-lcd-hd44780u-a00 lcd # Standard Japanese font
new hw-lcd-char-display display
# display size is in pixels - ie. font-width*display-height
set display width 40 # 8 chars X 5 pixels per char
set display height 8 # single line of 8 pixels
# connect the LCD to the display
connect-pin lcd row-col -> display row-col
connect-pin lcd FR -> display FR
| pins | |||
|---|---|---|---|
| name | direction | legalvalues | behaviors |
| FR | in | binary | display |
| row-col | in | 2 shorts as a 32-bit value | display |
| attributes | |||||
|---|---|---|---|---|---|
| name | category | legal values | default value | behaviors | |
| width | configuration | any positive value | 80 | configuration | |
| height | configuration | any positive value | 24 | configuration | |