Thanks Bruce, Paul and Steve,
And yes I did cheat, by using a module that I had already written.
I started writing VirtualPort in response to this post from Osiris
http://www.picbasic.co.uk/forum/showthread.php?t=3554
He was looking for a way to have a 16-bit port that was scattered across random pins. By the time I got it working, Melanie had already given him what he needed, so I didn't bother posting it.
But, I soon realized that it was going to be more usefull than originally intended so continued to add more macro's and features, and have managed to do some pretty cool stuff with it.
Here's how the 16-bit port for Osiris looked...This creates a full 16-bit bi-directional port that can be placed on ANY pins in ANY order.<HR>Code:MyPort VAR Word SYSTEM ASM MyPortPins macro ; these define which bits go with which pins Vpin 0, PORTB,0 Vpin 1, PORTC,4 Vpin 2, PORTA,0 Vpin 3, PORTC,1 Vpin 4, PORTC,3 Vpin 5, PORTC,0 Vpin 6, PORTA,1 Vpin 7, PORTC,5 Vpin 8, PORTB,2 Vpin 9, PORTB,3 Vpin 10, PORTC,2 Vpin 11, PORTC,0 Vpin 12, PORTB,4 Vpin 13, PORTB,6 Vpin 14, PORTB,5 Vpin 15, PORTC,7 endm ENDASM @ OutputPort MyPortPins @ WritePort MyPort, MyPortPins @ InputPort MyPortPins @ ReadPort MyPort, MyPortPins
Additional macros can also allow control of Direction, Enable, Latch pulses etc. in the same structure. Here's an 8-bit port with flow controlOr that can be simplified like this...Code:Direction VAR PORTB.5 Enable VAR PORTB.1 ASM Port8_Read macro PinLow _Direction ; Set direction pin for Read Vpin 0, PORTB,0 Vpin 1, PORTC,4 Vpin 2, PORTA,0 Vpin 3, PORTC,1 Vpin 4, PORTC,3 Vpin 5, PORTC,0 Vpin 6, PORTA,1 Vpin 7, PORTC,5 PulseLow Enable, 2 ; Low pulse for 2uS endm Port8_Write macro PinHigh _Direction ; Set direction pin for Write Vpin 0, PORTB,0 Vpin 1, PORTC,4 Vpin 2, PORTA,0 Vpin 3, PORTC,1 Vpin 4, PORTC,3 Vpin 5, PORTC,0 Vpin 6, PORTA,1 Vpin 7, PORTC,5 PulseLow Enable, 2 ; Low pulse for 2uS endm ENDASM @ OutputPort Port8_Write @ WritePort MyPort, Port8_Write @ InputPort Port8_Read @ ReadPort MyPort, Port8_Read<hr>Code:ASM Port8_Pins macro Vpin 0, PORTB,0 Vpin 1, PORTC,4 Vpin 2, PORTA,0 Vpin 3, PORTC,1 Vpin 4, PORTC,3 Vpin 5, PORTC,0 Vpin 6, PORTA,1 Vpin 7, PORTC,5 PulseLow Enable, 2 ; Low pulse for 2uS endm Port8_Read macro PinLow _Direction ; Set direction pin for Read Port8_Pins endm Port8_Write macro PinHigh _Direction ; Set direction pin for Write Port8_Pins endm ENDASM
Another similar question that keeps popping up every now and then, is how to use an LCD that's not connected to a contiguous nibble of a port.
This program allows you to do that, and also ties it in with LCDOUT for a "transparent" interface.Of course this relies on another program I wrote, "HighJack", to actually link in to LCDOUT. But nobody bothered to respond to this threadCode:INCLUDE "HighJack.bas" @ HighJack LCDOUT, _LCDsend Clear INCLUDE "VirtualPort.bas" ;----[ Change these to match your LCD ]--------------------------------------- LCD_DB4 VAR PORTB.0 LCD_DB5 VAR PORTB.4 LCD_DB6 VAR PORTC.6 LCD_DB7 VAR PORTC.3 LCD_RS VAR PORTD.1 LCD_E VAR PORTD.0 LCD_Lines CON 2 ' # of Lines on LCD, 1 or 2+ LCD_DATAUS CON 50 ' Data delay time in us LCD_COMMANDUS CON 2000 ' Command delay time in us ;----[Virtual LCD Port --- 4bit mode]----------------(Don't Change)----------- ASM LCD_Port_HNIB macro ; Port definition for LCD High Nibble Vbit LCDCDFLAG, _LCD_RS ; Select Command/Data register Vpin 4, _LCD_DB4 ; Put the High Nibble on the bus Vpin 5, _LCD_DB5 Vpin 6, _LCD_DB6 Vpin 7, _LCD_DB7 PulseLow _LCD_E, 2 ; pulse the Enable Pin for 2 us endm ;----------------------- LCD_Port_LNIB macro ; Port definition for LCD Low Nibble Vpin 0, _LCD_DB4 ; Put the Low Nibble on the bus Vpin 1, _LCD_DB5 Vpin 2, _LCD_DB6 Vpin 3, _LCD_DB7 PulseLow _LCD_E, 2 ; pulse the Enable Pin for 2 us endm OutputPort LCD_Port_HNIB ; Set LCD bus to OUTPUT ENDASM ;----[Main program starts here]----------------------------------------------- LoopCount VAR WORD Main: lcdout $FE,$80, dec LoopCount LoopCount = LoopCount + 1 goto Main ;----[Send a byte to the Virtual LCD PORT]--------called by LCDOUT------------ TempChar var byte Char VAR Byte LCD_Initialized VAR FLAGS.1 RSS VAR FLAGS.0 ; LCD RS State ;------- LCDsend: @ MOVE?AB _TempChar ; Get char sent by LCDOUT, in WREG if !LCD_Initialized then LCD_Init ; Make sure LCD was Initialized LCDAfterInit: if TempChar = $FE then RSS=0 : goto LCDsendDone ; next char is Command Char = TempChar LCDsendCOM: @ WritePort _Char, LCD_Port_HNIB ; send the High Nibble LCDsendShortCOM: @ WritePort _Char, LCD_Port_LNIB ; send the Low Nibble if LCD_RS OR (Char > 2) then PAUSEUS LCD_DATAUS ; Data delay time in us else PAUSEUS LCD_COMMANDUS ; Command delay endif if LCD_Initialized then RSS = 1 ; Set RS to Data next time LCDsendDone: return ;----[Initialize the LCD]----------------------------------------------------- LCD_Init: LOW LCD_RS : HIGH LCD_E ; Start with RS LOW and Enable High Char = 3 : gosub LCDsendShortCOM : pause 6 gosub LCDsendShortCOM : PAUSE 1 gosub LCDsendShortCOM : PAUSE 1 Char = 2 : gosub LCDsendShortCOM : PAUSE 1 ; Start 4-bit mode Char = $28 : gosub LCDsendCOM ; Function Set, 4-bit, 2-line, 5x7 Char = $0C : gosub LCDsendCOM ; Display ON Char = $01 : gosub LCDsendCOM ; Clear Screen Char = $06 : gosub LCDsendCOM ; Entry Mode LCD_Initialized = 1 ; LCD has been Initialized goto LCDAfterInit
http://www.picbasic.co.uk/forum/showthread.php?t=3290
so I never bothered posting it.
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