Erasecode,Writecode,Readcode - again

[Darrel Taylor]

OK, after those results, I'm compelled to go out on a limb.

That limb is to say that...

1. PBP is wrong, by declaring BLOCK_SIZE as 64 bytes. But I can't blame them, because....
2. Microchip is wrong, since their datasheet says the Flash must be written 64 bytes at a time.

It seems apparent that the 18F8722 only has 8 holding registers for flash writes (regardless of what the datasheet says). It does erase 64 bytes at once. But you can only write 8 bytes at a time. Coincidently, that's the same as the 18F8720, it's predecessor.

I may be eating crow by the next post. But I'm pretty sure this will work...

AA VAR WORD
BB VAR WORD
CC VAR WORD
DD VAR WORD
 X VAR BYTE
 
ERASECODE $1F00

TBLPTRU = 0
TBLPTRH = $1F
TBLPTRL = 0
for X = 0 to 7
    gosub Write8
next X

Gosub ShowFlash

stop
;_____________________________________________
Write8:
    For BB = 0 to 7
        TABLAT = BB.Lowbyte
        @ tblwt*+
    NEXT BB
    TBLPTRL = TBLPTRL - 1
    EECON1 = $84
    EECON2 = $55
    EECON2 = $AA
    ASM
        bsf   EECON1, WR
        nop
        bcf   EECON1, WREN
    endasm
    TBLPTRL = TBLPTRL + 1
return

ShowFlash:
    For CC = $1F00 to $1F3F STEP 2
        READCODE CC,DD
        HSEROUT [HEX4 CC," ",HEX4 DD,13,10]
    NEXT CC
    HSEROUT [10]
return

Then, assuming that works. Simply changing BLOCK_SIZE EQU 64 to, BLOCK_SIZE EQU 8 in the 18F8722.INC file should fix it.

The only thing I have here to test it on is an 18F6720, which is also Erase 64/write 8. And it works here....

Prepare to feed me my Crow.
<br>

[Charles Linquis]

WORKS!

Thanks again!



Anybody from Microchip out there listening? You owe Darrel at least a dinner!

[skimask]

WORKS!

Thanks again!



Anybody from Microchip out there listening? You owe Darrel at least a dinner!

And I have to wonder how and why my PICKIT2 works with the '8722 if it's actually using the datasheet specifications.
Apparently, Microchip is holding out on the datasheet info and/or revisions/errata again...

[Darrel Taylor]

WORKS!

Oh thank God!
It's always so hard to get the feathers out of my teeth.

[Charles Linquis]

Thanks to a mis-labeled board (it actually had an 8720 on it, rather than an 8722), I really got things screwed up.

And it turns out that MC's documentation is indeed correct - the 8720 has a block size of 8 bytes, while the 8722 has a block size of 64 bytes.

Everything is working now. I *would* let Darrel feed me some of that crow, but I'm a vegetarian !

[Darrel Taylor]

And let that be a lesson to everyone.

Never trust your test equipment unconditionally.
Especially when it's not electronic.

Ok well, I suppose I'll have a few feathers for dinner, but I can see you're not going to chow down willingly, mr vegan. So just to make sure, I've put a heaping helping in your avatar.

[Archangel]

And let that be a lesson to everyone.

Never trust your test equipment unconditionally.
Especially when it's not electronic.

Ok well, I suppose I'll have a few feathers for dinner, but I can see you're not going to chow down willingly, mr vegan. So just to make sure, I've put a heaping helping in your avatar.

I'll trade ya some spaghetti for some of that crow

[Darrel Taylor]

Spaghetti sounds good.

But some floss for the feathers would be better.
<br>

[ImAnEE]

Good golly, this works. I fussed around with PBP WRITECODE for way too long and gave up, modified Darrel's code slightly, and it works! Here's my code. Thanks Darrel!

Code for PIC18F8722:

FOR IX = 0 TO 63 ' for DEBUG
FLASH_WRITE_BUFF[IX] = IX + 64 ' for DEBUG
NEXT IX ' for DEBUG
' DEBUG WRITE FLASH PROGRAM MEM TEST
ERASECODE FLASH_MEM_START
FOR IX = 0 TO 63 ' load TBLAT
TABLAT = FLASH_WRITE_BUFF[IX]
@ tblwt*+
NEXT IX
TBLPTRL = FLASH_MEM_START
EECON1 = $84
EECON2 = $55
EECON2 = $AA
ASM
BSF EECON1, WR
NOP
BCF EECON1, WREN
ENDASM
TBLPTRL = TBLPTRL + 1
' DONE WRITING FLASH PROGRAM MEM TEST