Re: [Flashforth-devel] flashforth on p18f4550 - No usb?

[Pete Z. <pza...@pz...>]

Hi Scott,

That is great news...Good luck with FF on the 4550.  I use the PICDEM 
FSUSB Demo board here for the USB testing.

I generally go to the PIC Data Sheet  for the particular processor and 
study the Oscillator Configuration section carefully.
One way or another, you will need  20MHz  for the USB.   Other internal 
frequencies will be your decision.

As another example, for the 18F6527 FF3.8 with UART at 38.4K baud, I 
change the following:

ff18_usb.asm

FROM:
#ifdef OSCCON
         movlw   0x70            ; Use full internal OSC frequency
         movwf   OSCCON, A
#endif

TO:
; ppz osc
; ------------------------------------------------------------
#ifdef __18F6527
; Internal Oscillator
         movf    OSCCON, W, A
         iorlw   b'01110000'            ; 8MHz
         movwf   OSCCON, A
         nop
; Enable Oscillator PLL
         movf    OSCTUNE, W, A
         iorlw   b'01000000'            ; Enable PLL for 4x8MHz
         movwf   OSCTUNE, A
         nop
         nop
#else
#ifdef OSCCON
         movlw   0x70            ; Use full internal OSC frequency
         movwf   OSCCON, A
#endif

#endif
; ------------------------------------------------------------

p18f-main.cfg

;;;;  PIC18F6527 Internal Oscillator with PLL
         constant clock = d'32000000'

p18fxxxx.cfg

         ifdef __18F6527
             #include p18f6527.inc
;;;            #include p18f6722-family.cfg
             #include p18f6527.cfg
             #define  PICTYPE "PIC18F6527 "
             #define FLASH_HI  0xbfff
             #define EEPROM_HI 0xefff
             #define RAM_HI    0xff60
         endif

And add the following file:

;**********************************************************************
;                                                                     *
;    Filename:      p18f6527.cfg                                      *
;    Date:          4:23 PM 10/4/2011                                 *
;    FF Version:    3.8                                               *
;    Copyright:     Pete Zawasky                                      *
;    Author:        Pete Zawasky                                      *
;                                                                     *
;**********************************************************************
;    Based on p18f6722-family.cfg by Mikael Nordman                   *
;**********************************************************************
;    FlashForth is licensed acording to the GNU General Public License*
;**********************************************************************
;;; FlashForth processor specific configuration

; The config directive is used control the processor configuration bits
; See processor specific include file for details.


#if CONFIG_RESET == 0x0000
         config OSC = INTIO67
         config FCMEN = OFF
         config IESO = OFF
         config PWRT = OFF
         config BOREN = SBORDIS
         config BORV = 3
         config WDT = OFF
         config WDTPS = 32768
         config MCLRE = ON
         config LPT1OSC = ON
         config CCP2MX = PORTC
         config STVREN = ON
         config LVP = OFF
         config BBSIZ = BB8K
         config XINST = OFF
         config DEBUG = OFF
         config CP0 = OFF
         config CP1 = OFF
         config CP2 = OFF
         config CPB = OFF
         config CPD = OFF
         config WRT0 = OFF
         config WRT1 = OFF
         config WRT2 = OFF
         config WRTB = ON
         config WRTC = ON
         config WRTD = OFF
         config EBTR0 = OFF
         config EBTR1 = OFF
         config EBTR2 = OFF
         config EBTRB = OFF

#endif

;;; Some constants controlling how writes to program flash is made.
         constant flash_write_outer_loop = d'1'
         constant flash_write_inner_loop = d'64'
;**********************************************************************

As you can see, one has to really focus on the particular processor for 
the OSC, PLL, and CONFIGURATION bits.
Then I really pound away on Mikael's FF code to see if it really works 
like he says it should....

A software test suite (validation suite) for FF like we had in eFORTH 
would really be great.
In the mean time,  try all the different applications you can with lots 
of different words and learn FF.

Pete