PIC16F677 and READ/WRITE

[LinkMTech]

Hi all,
I've been using both 16F677 and 16f685 chips as availability allowed with same program without any problems until I introduced the READ and WRITE functions on the 16F677.
I get the error: Error[113]: Symbol not previously defined (EEPGD)
The data sheet shows:

10.1.1 EECON1 AND EECON2 REGISTERS EECON1 is the control register for EE memory accesses. Control bit EEPGD (PIC16F685/PIC16F689/PIC16F690) determines if the access will be a program or data memory access.

And also when referring to EECON1.7:

Note 1: PIC16F685/PIC16F689/PIC16F690 only.

I stripped the code down to a minimum to compile with READ and WRITE commented out or not to see if it compiles without error using PICBasic Pro 2.47 and MPASM.

This is only a sample routine to demo the compilation error. I hope that someone can shed some light on this.

'*************************************************************************
@ __config _INTRC_OSC_NOCLKOUT & _WDT_OFF & _MCLRE_OFF & _CP_ON & _BOR_OFF

OSCCON = %01001000      ' Oscillator set to 1MHz
PORTA = %00000000       ' Turn off all PORTA
ANSEL = 0               ' Sets all PORTA inputs to digital inputs 
TRISA = %00011111       ' Sets all PORTA pins as inputs except RA5
PORTB = %00000000       ' Turn off all PORTB
ANSELH = 0              ' Sets analog inputs 8 ~ 11 to digital inputs
TRISB = %10000000       ' Sets RB4~6 as outputs and RB7 as input
PORTC = %00000000       ' Turn off all PORTC
TRISC = %00000000       ' Sets all PORTC pins as outputs
CM1CON0.7 = 0		    ' Analog comparator #1 off
CM1CON0.5 = 0           ' Comparator #1 output disabled
CM2CON0.7 = 0           ' Analog comparator #2 off
CM2CON0.5 = 0           ' Comparator #0 output disabled
ADCON0 = 0              ' A/D OFF
OPTION_REG.7 = 1        ' Global weak pull-up enable bit enabled
WPUA = %00010111        ' Weak pull-ups enable on PORTA inputs
WPUB = %00000000        ' Weak pull-ups disabled on PORTB inputs

'=========================================================================
'                           Variables       
'=========================================================================
x       VAR BYTE        

'=========================================================================
' Set EEPROM default value at location 2 for 2 Modes at initial program
' then this value is user selectable via Mode button.
'=========================================================================
    EEPROM 2, [2]
    PAUSE 10
           
'=========================================================================
'                           Test loop       
'=========================================================================
x = 7
loop:                       
        READ 2, x
        PAUSE 10
'        WRITE 2, x
        PAUSE 10
GOTO loop

END

Thank you all for your input...

[LinkMTech]

I guess this was a tough one and don't feel so bad now. After researching and more searching it became obvious.
Even though the PIC16F677 has 256 bytes of EEPROM availble but I can't use it because it seems the compiler is trying to use EEPGD that is only used in the rest of the series... Don't use it!
The PIC16F685, 687, 689 & 690 are only around $0.25 more. Problem solved.

[LinkMTech]

Well as it turns out, just avoiding the problem did not solve it.
The PIC16F685 does not provide the SSP hardware I'll be needing now so more searching found Darrel's guidance (thanks again Darrel!) http://www.picbasic.co.uk/forum/showthread.php?t=12424
So comparing both INC files shows that the PIC16F677 was missing the EEPGD in the BANK 3 Register:

portion of PIC16F685 INC file:

;----- BANK 3 REGISTER DEFINITIONS ----------------------------------------
;----- EECON1 -------------------------------------------------------------

EEPGD                        EQU     H'0007'
WRERR                        EQU     H'0003'
WREN                         EQU     H'0002'
WR                           EQU     H'0001'
RD                           EQU     H'0000'

same section of PIC16F677 INC file:

;----- BANK 3 REGISTER DEFINITIONS ----------------------------------------
;----- EECON1 -------------------------------------------------------------

WRERR                        EQU     H'0003'
WREN                         EQU     H'0002'
WR                           EQU     H'0001'
RD                           EQU     H'0000'

Updated to:

;----- BANK 3 REGISTER DEFINITIONS ----------------------------------------
;----- EECON1 -------------------------------------------------------------

EEPGD                        EQU     H'0007' ; Added 11/8/2010
WRERR                        EQU     H'0003'
WREN                         EQU     H'0002'
WR                           EQU     H'0001'
RD                           EQU     H'0000'

Compiled without errors and I can now use the EEPROM in the PIC16F677!

A big Thank You! to all who contribute their expertise and time to help others along.

[Darrel Taylor]

Hi Louie,

I'm glad you got it working, although I'm not sure how my other post helped.

Would it help if I mentioned that 2.47 was the first time that family was included in PBP.
And the 677 EEPROM issue was fixed in PBP version 2.50?

OK, probably not ...
________________
DT

[LinkMTech]

Would it help if I mentioned that 2.47 was the first time that family was included in PBP.
And the 677 EEPROM issue was fixed in PBP version 2.50?

Actually it does...
It confirms I need to stop dragging my feet and dig out my receipt for Bruce so I can update!