Converting to MPASM

[btaylor]

Hello Melanie.

As you suggested, I went to the microchip homepage and clicked QUICKLINKS then Development Software and downloaded the 38 Mbyte zip file of MPLAB IDE ver 7.22 which I believe to be the latest version. MPLAB includes MPASM.

I unzipped this into a directory C:\MPASM. From that directory I clicked MPLAB_v722.exe and let it install the full MPLAB system to the default directory C:\program files\microchip\etc.

I then loaded MicroCode Studio Plus, (ver 2.2.1.1) and clicked view\Compile & Programme Options then made MPASM as the default compiler. MPASM was found automatically.

I am running PBP ver 2.46 and have an incomplete, but running, program of 370 lines. The target processor is a PIC16F877 and I am using the MCSP Bootloader to program the chip. This compiles under PBP/PM to 2715 words with no errors. The first few lines of this program are attached.

Under PBP/PM, the following configuration line is active.
@ Device pic16F877, HS_OSC, BOD_OFF, PWRT_ON, WDT_ON, PROTECT_OFF

To suit MPASM, I changed this to
@ _config_HS_OSC &_BOD_OFF &_PWRT_ON &_WDT_ON &_PROTECT_OFF

I get 1259 errors when I try to compile under MPASM, zero errors under PBP/PM.

CHeers
Brian

Here is the start of the program. This snippet does compile under PBP/PM but not under MPASM.

data @0, "DeckUnit v5.00 BDT 3 NOV 05 "
data @30, 01, $E0, $15, 200, 50 ' ID, Fcntr.lo, Fcntr.hi, Fdev, bitrate
data @35, 0, 5, 12, 48 ' MasterSlave, matches, syncbits, repeats
data @39, 0, 60 ' TxPower, sleeptime

'************************************************* ********
'* Name : DeckUnit500.PBP *
'* : *
'************************************************* ********

DEFINE OSC 20
DEFINE loader_used 1
DEFINE CHAR_PACING 1000
DEFINE LCD_DREG PORTD
DEFINE LCD_DBIT 0
DEFINE LCD_RSREG PORTD
DEFINE LCD_RSBIT 5
DEFINE LCD_EREG PORTD
DEFINE LCD_EBIT 4
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 500

@ Device pic16F877, HS_OSC, BOD_OFF, PWRT_ON, WDT_ON, PROTECT_OFF
'@ _config_HS_OSC &_BOD_OFF &_PWRT_ON &_WDT_ON &_PROTECT_OFF

trisa = %11111111
trisb = %11111111
trisc = %10011111
trisd = %00000000
trise = %00000000
OPTION_REG = %10001111 ' no pullups, prescaler to WDT /128

'***************** Hardware definition **********************
DiagLED var porta.0 ' Olimex standard LED
GoLED var portc.5 ' pin 24 on '877

'******************* Software variables **********************
A var byte
B var byte

'*************************** Initialise ********************************
Startup:
Initialise:
OPTION_REG = %00001111 ' no pullups, prescaler to WDT /128
INTCON = %00000000
PIE1 = %00110000
PIE2 = %00000000 ' guessing here
ADCON1 = %00000111
TRISE = %00000000
CCP1CON = %00000000

TestLED:
for a = 0 to 9
high goled
high diagled
pause 100
low goled
low diagled
pause 100
next a
trisa = %11111111

[btaylor]

My problems with MPASM appears to be a path, path length, or similar problem. Plus a remnant @ _config_ issue.

I found a comment on the PICBasic List.

(quote) When ever I use MPLAB I make sure there is a full copy of PBP in the Mplab directory and place my PBP program in the directory too. This prevents all
the problem with paths etc. (endquote)

I also found other comments that the total path length must be short so I shifted my code from 'my documents' up to an entry in c:\ and I copied all my PBP files to c:\program files\microchip\MPASM Suite.

It nearly works now. I still get errors when I use the line
@ _config_HS_OSC &_BOD_OFF &_PWRT_ON &_WDT_ON &_PROTECT_OFF

If I comment that line out completely I get no errors, just warnings about page boundaries which I assume PBP has taken care of for me. I would rather have the explicit configuration line active.

Nearly there maybe. What a drama.

Cheers
Brian

[Darrel Taylor]

Hi Brian,

In the CONFIG line for MPASM, there must be 2 underscores before the word CONFIG, and a space after it. And some of the options should be different

@ __CONFIG _HS_OSC &_BODEN_OFF &_PWRTE_ON &_WDT_ON &_CP_OFF

And keep in mind that MPASM is CASE Sensitive (unless you use the command line option to disable case sensitivity).

HTH,
   Darrel

[btaylor]

Thanks Darrel,

I copied your line into my code. It tellls me I now have 2 errors but only one error gets shown with three messages on the bottom of the MCSP screen.

Error [118].....Overwriting previous address contents (2007)
Message [306] Crossing page boundary..ensure page bits are set.
Message [306] Crossing page boundary..ensure page bits are set.
Message [306] Crossing page boundary..ensure page bits are set.

Do the page bits get set autometically?

What does error 118 mean and how do I fix it?

Brian

[Darrel Taylor]

2007 is the address of the CONFIG word in the PIC. The "error [118] Overwriting previous address contents" means that it's already been set.

In the 16F877.inc file in your PBP folder, comment out the __CONFIG line with a semicolon ";" Then try again.

Just remember, that once commented, every time you write a program for a 16F877, you''l need to have a CONFIG line at the top of your program, since the defaults aren't there anymore.

You may also want to add _LVP_OFF to the CONFIG in your program to turn off the Low Voltage Programming input.

And <b>@ errorlevel -306</b> will turn off the Crossing page boundary warnings
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