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WildMax
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| Hardware I2C doesn work |
 Posted: Tue Jul 26, 2005 9:54 am |
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Please help me.
I' m trying to get this short peace of code working, but I always get a software I2C. Why??
| Code: | #include <16F747.h>
#use delay(clock=31250)
#fuses NOWDT,INTRC_IO, NOPUT, NOPROTECT, NOBROWNOUT, BORV20, MCLR, NODEBUG, NOFCMEN, NOIESO, NOBORSEN
#use I2C(slave,sda=PIN_C4,scl=PIN_C3,address=0xa0,FORCE_HW)
void main()
{
i2c_Start();
i2c_Write(64);
i2c_Stop();
}
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Compiler Version is 3.203
MPLAB Version is 7.20
Please help me!
Thanks a lot |
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WildMax
Guest
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| Posted: Tue Jul 26, 2005 9:57 am |
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Oh, the assembled code is:
| Code: |
1: #include <16F747.h>
000 3000 MOVLW 0
001 008A MOVWF 0xa
002 282D GOTO 0x2d
003 0000 NOP
2:
3: #use delay(clock=31250)
4: #fuses NOWDT,INTRC_IO, NOPUT, NOPROTECT, NOBROWNOUT, BORV20, MCLR, NODEBUG, NOFCMEN, NOIESO, NOBORSEN
5:
6: #use I2C(slave,sda=PIN_C4,scl=PIN_C3,address=0xa0,FORCE_HW)
004 3008 MOVLW 0x8
005 00F8 MOVWF 0x78
006 1683 BSF 0x3, 0x5
007 1587 BSF 0x7, 0x3
008 1207 BCF 0x7, 0x4
009 1283 BCF 0x3, 0x5
00A 1D87 BTFSS 0x7, 0x3
00B 280E GOTO 0xe
00C 1683 BSF 0x3, 0x5
00D 2809 GOTO 0x9
00E 0DA1 RLF 0x21, F
00F 1803 BTFSC 0x3, 0
010 1607 BSF 0x7, 0x4
011 1C03 BTFSS 0x3, 0
012 1207 BCF 0x7, 0x4
013 1D87 BTFSS 0x7, 0x3
014 2813 GOTO 0x13
015 0BF8 DECFSZ 0x78, F
016 2818 GOTO 0x18
017 281A GOTO 0x1a
018 1683 BSF 0x3, 0x5
019 2809 GOTO 0x9
01A 1987 BTFSC 0x7, 0x3
01B 281A GOTO 0x1a
01C 1683 BSF 0x3, 0x5
01D 1607 BSF 0x7, 0x4
01E 1283 BCF 0x3, 0x5
01F 1987 BTFSC 0x7, 0x3
020 2823 GOTO 0x23
021 1683 BSF 0x3, 0x5
022 281E GOTO 0x1e
023 01F8 CLRF 0x78
024 1A07 BTFSC 0x7, 0x4
025 1478 BSF 0x78, 0
026 0000 NOP
027 1683 BSF 0x3, 0x5
028 1187 BCF 0x7, 0x3
029 1283 BCF 0x3, 0x5
02A 1187 BCF 0x7, 0x3
02B 118A BCF 0xa, 0x3
02C 284B GOTO 0x4b
7:
8: void main()
9: {
02D 0184 CLRF 0x4
02E 301F MOVLW 0x1f
02F 0583 ANDWF 0x3, F
030 1683 BSF 0x3, 0x5
031 081F MOVF 0x1f, W
032 39C0 ANDLW 0xc0
033 3803 IORLW 0x3
034 009F MOVWF 0x1f
035 3007 MOVLW 0x7
036 1283 BCF 0x3, 0x5
037 009F MOVWF 0x1f
10:
11: i2c_Start();
038 1683 BSF 0x3, 0x5
039 1587 BSF 0x7, 0x3
03A 1607 BSF 0x7, 0x4
03B 1283 BCF 0x3, 0x5
03C 1A07 BTFSC 0x7, 0x4
03D 2840 GOTO 0x40
03E 1683 BSF 0x3, 0x5
03F 283B GOTO 0x3b
040 1D87 BTFSS 0x7, 0x3
041 2840 GOTO 0x40
042 1987 BTFSC 0x7, 0x3
043 2840 GOTO 0x40
044 1683 BSF 0x3, 0x5
045 1187 BCF 0x7, 0x3
046 1283 BCF 0x3, 0x5
047 1187 BCF 0x7, 0x3
12: i2c_Write(64);
048 3040 MOVLW 0x40
049 00A1 MOVWF 0x21
04A 2804 GOTO 0x4
13: i2c_Stop();
04B 1683 BSF 0x3, 0x5
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WildMax
Guest
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| Posted: Tue Jul 26, 2005 10:01 am |
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Oh, i haven't seen, that the #use i2c statement was for a slave but if i change it to master, the same problem occours!!
Please help me, it is really important and has to go very quick!! |
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Ttelmah
Guest
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| Posted: Tue Jul 26, 2005 10:04 am |
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Probably because a slave device, cannot issue a 'start' on I2C.
The whole point is that with a slave, the _master_ allways begins and ends the transaction. As soon as you use the 'start', and 'stop' commands, you are overriding the instruction to be a hardware slave.
Best Wishes |
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Guest
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| Posted: Tue Jul 26, 2005 10:07 am |
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| Ttelmah wrote: | Probably because a slave device, cannot issue a 'start' on I2C.
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Yeah, i know that, but if i change it to master, there are not many changes (its also software) |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Tue Jul 26, 2005 10:15 am |
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Your version of the compiler doesn't create hardware i2c code.
I tested your version and then installed vs. 3.228, and the later
version does create code for H/W i2c.
If you have PCW or PCWH, you could use the Device Editor to
see if CCS has properly configured the 16F747. This screenshot
of the Device Editor shows two check boxes for i2c Slave and i2c Master.
http://www.ccsinfo.com/pix/Device%20Editor.gif
You could also upgrade the compiler or write the H/W i2c functions
yourself. |
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mwildbolz
Joined: 26 Jul 2005
Posts: 16
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| Posted: Tue Jul 26, 2005 10:20 am |
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in my compiler version, i2c Master is enabled, but i2c slave not.
I'll try to change this and then i'll try it on a newer compiler version
Thanks |
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mwildbolz
Joined: 26 Jul 2005
Posts: 16
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| Posted: Tue Jul 26, 2005 10:22 am |
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OK!
I've found the problem!
In the device editor, both has to be enabled (i2c master AND slave).
In my case, only Master was enabled and therfore, the compiler wasn't able to produce code for HW - I2C
Thanks for your help |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Tue Jul 26, 2005 10:25 am |
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It's possible that CCS left the i2c slave box unchecked because
they didn't have it working at the time of the release.
You should look at the ASM code produced for the i2c Slave and
verify that it's correct.
That's what I would do, just to be safe. |
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mwildbolz
Joined: 26 Jul 2005
Posts: 16
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| Posted: Tue Jul 26, 2005 10:33 am |
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I think, now it is in the right form:
| Code: | 6: #use I2C(master,sda=PIN_C4,scl=PIN_C3,FORCE_HW)
004 1394 BCF 0x14, 0x7
005 118C BCF 0xc, 0x3
006 0821 MOVF 0x21, W
007 0093 MOVWF 0x13
008 3002 MOVLW 0x2
009 1B94 BTFSC 0x14, 0x7
00A 2812 GOTO 0x12
00B 1D8C BTFSS 0xc, 0x3
00C 280B GOTO 0xb
00D 3000 MOVLW 0
00E 1683 BSF 0x3, 0x5
00F 1B11 BTFSC 0x11, 0x6
010 3001 MOVLW 0x1
011 1283 BCF 0x3, 0x5
012 00F8 MOVWF 0x78
013 118A BCF 0xa, 0x3
014 2841 GOTO 0x41 |
Thats the listing directly under the #use i2c
And this lines use the SSP registers |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Tue Jul 26, 2005 10:36 am |
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| I didn't mean that. I meant, check the code to make sure it works. |
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mwildbolz
Joined: 26 Jul 2005
Posts: 16
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| Posted: Tue Jul 26, 2005 10:39 am |
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Oh, clear.
I'll check it and report as soon as possible! |
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Guest
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| Posted: Tue Jul 26, 2005 11:32 am |
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OK, i've tested the Code and all is OK!
I'm happy 
I wish you a nice day |
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mwildbolz
Joined: 26 Jul 2005
Posts: 16
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| Posted: Tue Jul 26, 2005 11:33 am |
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Sorry, i've forgotten to log in
regards, Markus |
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