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dictionary:4-bit_mode [2007/11/17 17:18] |
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+ | 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]] |