User Tools

Site Tools


4-bit_mode

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revisionPrevious revision
4-bit_mode [2006/10/15 09:35] – (old revision restored) 127.0.0.14-bit_mode [2007/11/17 17:21] (current) – removed smashtv
Line 1: Line 1:
-Since version mios_v1_5b [[http://www.ucapps.de/mios.html|MIOS]] has supported 4-bit mode for HD44780 compatible displays\\ 
  
-Usually this mode isn't needed, but some displays have been internally configured for 4-bit operation and don't have all the necessary connections for full 8-bit operation or You might have some other reason to try this mode out. 
- 
-To configure [[http://www.ucapps.de/mios.html|MIOS]] application to use 4-bit CLCD mode, changes need to be made to the application:\\ 
- 
-First locate\\ **'USER_Init'** section of the source files ((usually in 'main.asm', in MB_SID 'sid_init.inc')) 
- 
-Then add to its own section just below the 'USER_Init' ((Don't add it in between the initialization commands or you can break something this way)): 
- 
-  
-       ;; use a CLCD, E input of first CLCD at D.7, E of second CLCD @C.4 
-       ;; using the 4-bit interface: 
-       ;; -> connect MBHP_CORE:J15:D7-D4 of the core module to D7-D4 of the LCD 
-       ;; -> left MBHP_CORE:J15:D3-D0 of the core module open! 
-       ;; -> tie D3-D0 of the LCD to ground 
-       movlw   0x37 | 0x80     ; E1: D.7, 4bit interface 
-       movwf   MIOS_PARAMETER1 
-       movlw   0x24 | 0x80     ; E2: C.4, 4bit interface 
-       movwf   MIOS_PARAMETER2 
-       movlw   0x00            ; LCD type 0 
-       call    MIOS_LCD_TypeSet'' 
- 
-Then you have to Compile the modified application. 
- 
-See the comments ((marked with ;; in the beginning of the line)) in the code for how to connect the display to the core. In the display side, having the datasheet for it helps a lot. 
- 
-More: [[http://www.ucapps.de/mios_fun.html#MIOS_LCD_TypeSet|MIOS function reference]] 
4-bit_mode.1160904901.txt.gz · Last modified: 2007/11/17 17:21 (external edit)