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allenhuffman
Joined: 17 Jun 2019
Posts: 552
Location: Des Moines, Iowa, USA
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| Is source for I2C functions provided? |
 Posted: Thu Aug 22, 2019 1:46 pm |
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Is the source code for any of the built in library functions, specifically I2C, available?
_________________
Allen C. Huffman, Sub-Etha Software (est. 1990) http://www.subethasoftware.com
Embedded C, Arduino, MSP430, ESP8266/32, BASIC Stamp and PIC24 programmer.
http://www.whywouldyouwanttodothat.com ? |
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newguy
Joined: 24 Jun 2004
Posts: 1908
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| Posted: Thu Aug 22, 2019 2:02 pm |
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Near the top of each processor's include file, for example "18F452.h" will be a #nolist. Comment that out and recompile. I believe that whatever built-in functions you use will then be visible in the list file (disassembly).
Also note that the compiler can be set to use register names/variable names in the list file. Project->Output Files->List File. Relevant boxes are SFR Names, Symbols, Interpret. |
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temtronic
Joined: 01 Jul 2010
Posts: 9228
Location: Greensville,Ontario
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| Posted: Thu Aug 22, 2019 2:04 pm |
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Yes, all compiled code can be seen in the listing, though you may need to delete the '#nolist' option for some drivers.
also
the listing is NOT in 'program memory' order |
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allenhuffman
Joined: 17 Jun 2019
Posts: 552
Location: Des Moines, Iowa, USA
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| Posted: Thu Aug 22, 2019 2:49 pm |
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Thanks ... I'm not sure I am looking in the proper place. I commented out #nolist, then it wanted me to save it with the project. I did that, and then even put a #error line in to make sure it was reference MY copy (it is -- I changed the #include <file> to "file" like normal C, which might not have been necessary).
I don't think I saw the generated asm from this. I do see a bunch (half a dozen or more) blank "....." lines with the _bif prototype of i2c_read() but no related assembly. I searched through the 82,000+ lines of the list file for the "i2c_read" references but didn't find any asm that wasn't for the calls in our code.
_________________
Allen C. Huffman, Sub-Etha Software (est. 1990) http://www.subethasoftware.com
Embedded C, Arduino, MSP430, ESP8266/32, BASIC Stamp and PIC24 programmer.
http://www.whywouldyouwanttodothat.com ? |
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temtronic
Joined: 01 Jul 2010
Posts: 9228
Location: Greensville,Ontario
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| Posted: Thu Aug 22, 2019 3:09 pm |
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Here's a snippet from my modified DS3231 RTC driver..It's similar to the DS1307 driver and the 1st one that know has I2C functions in it...
from the .lst file...
| Code: |
.................... rtcsec = bcd2bin(i2c_read() & 0x7f);
03656: MOVLW 01
03658: MOVWF 00
0365A: CALL 0148
0365E: MOVF 01,W
03660: ANDLW 7F
03662: MOVWF xBD
03664: MOVWF xC2
03666: CALL 0196
0366A: MOVFF 01,10 |
I know the code works... |
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allenhuffman
Joined: 17 Jun 2019
Posts: 552
Location: Des Moines, Iowa, USA
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| Posted: Thu Aug 22, 2019 3:44 pm |
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Ah, I see. I'm seeing the code in-lined, rather than finding the i2c_read() function somewhere else?
_________________
Allen C. Huffman, Sub-Etha Software (est. 1990) http://www.subethasoftware.com
Embedded C, Arduino, MSP430, ESP8266/32, BASIC Stamp and PIC24 programmer.
http://www.whywouldyouwanttodothat.com ? |
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jeremiah
Joined: 20 Jul 2010
Posts: 1349
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| Posted: Thu Aug 22, 2019 4:53 pm |
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| In some cases yes. For situations that they use non inlined functions, at least for me in the PCD compiler, it shows the functions under their respective "#use" directive in the disassembly. |
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temtronic
Joined: 01 Jul 2010
Posts: 9228
Location: Greensville,Ontario
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| Posted: Thu Aug 22, 2019 5:04 pm |
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Here's what the code at CALL 0148 looks like.
Obviously no comments, though if you look at the PIC instruction set and SFR list, you can decode what is happening.
| Code: |
00148: MOVLW 08
0014A: MOVWF xC2
0014C: MOVFF 00,C3
00150: BSF F94.4
00152: BRA 0154
00154: NOP
00156: BSF F94.3
00158: BTFSS F82.3
0015A: BRA 0158
0015C: BTFSC F82.4
0015E: BSF FD8.0
00160: BTFSS F82.4
00162: BCF FD8.0
00164: RLCF 01,F
00166: BRA 0168
00168: BCF F94.3
0016A: BCF F8B.3
0016C: DECFSZ xC2,F
0016E: BRA 0150
00170: BSF F94.4
00172: BRA 0174
00174: NOP
00176: BCF F8B.4
00178: MOVF xC3,W
0017A: BTFSS FD8.2
0017C: BCF F94.4
0017E: NOP
00180: BSF F94.3
00182: BTFSS F82.3
00184: BRA 0182
00186: BRA 0188
00188: BCF F8B.3
0018A: BCF F94.3
0018C: BRA 018E
0018E: NOP
00190: BCF F8B.4
00192: BCF F94.4
00194: RETLW 00
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Hopefully I'm not breaking the 'rules'...this code is available for all to see. If I have please let me know.
The other call (196 ?) goes to the BINBCD routines.
Jay |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19515
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| Posted: Fri Aug 23, 2019 1:22 am |
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and (of course) if you switch the compiler to 'symbolic' mode, it'll tell
you the register names etc.. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Aug 23, 2019 2:34 am |
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| allenhuffman wrote: |
I don't think I saw the generated asm from this. I do see a bunch (half a
dozen or more) blank "....." lines with the _bif prototype of i2c_read() but
no related assembly. |
In the .LST file, the i2c code will be placed underneath the #use i2c()
statement. Example:
| Code: | .................... #use i2c(master, i2c1, slow)
000AE: BCF SSP1CON1.SSPOV
000B0: BSF SSP1CON2.RCEN
000B2: BTFSC SSP1CON2.RCEN
000B4: BRA 00B2
000B6: BTFSC 00.0
000B8: BCF SSP1CON2.ACKDT
000BA: BTFSS 00.0
000BC: BSF SSP1CON2.ACKDT
000BE: BSF SSP1CON2.ACKEN
000C0: BTFSC SSP1CON2.ACKEN
000C2: BRA 00C0
000C4: MOVFF SSP1BUF,01
000C8: RETURN 0 |
The above code is for i2c_read() for the 18F46K22.
| allenhuffman wrote: |
I searched through the 82,000+ lines of the list file for the "i2c_read"
references but didn't find any asm that wasn't for the calls in our code. |
You won't see labels for the CCS Library code in the .LST file or
in the View / Assembly Listing. You will see them in View / Program
Memory. (This is in MPLAB vs. 8.92) Here is the beginning of the code,
to show how the label is displayed:
| Code: |
Line Address Opcode Label Disassembly
88 00AE 9CC6 @I2C_READU_ BCF SSP1CON1, 0x06, ACCESS
89 00B0 86C5 BCF SSP1CON2, 0x03, ACCESS
90 00B2 B6C5 BTFSC SSP1CON2, 0x3, ACCESS
91 00B4 D7FE BRA 0xb2
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Ttelmah
Joined: 11 Mar 2010
Posts: 19515
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| Posted: Fri Aug 23, 2019 3:34 am |
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Just a slight 'eppend' to this.
The labels are present in the .sym file. So (for example), on a project of mine:
In the sym:
00110A @I2C_WRITEU_1
and (compiled with SFR names selected), the .lst gives:
| Code: |
.................... #USE I2C(I2C1, FAST=400000, STREAM=EEPROM) //EEPROM uses ALTI2C1 connections
*
0110A: MOV #FFFF,W0
0110C: BTSS.B I2C1STAT.S
0110E: BRA 111A
01110: BTSC.B I2C1STAT.TRSTAT
01112: BRA 1110
01114: MOV W1,I2C1TRN
01116: BTSC.B I2C1STAT.TRSTAT
01118: BRA 1116
0111A: MOV #0,W0
0111C: BTSC.B I2C1STAT.ACKSTAT
0111E: INC W0,W0
01120: RETURN
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So 'where' the routine is is in the .sym file, and the code for this is in
the .lst file. |
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