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Kasper
Joined: 14 Jan 2004
Posts: 88
Location: Aurora, Ontario, Canada
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| Assembly to C. Code not working right :( |
 Posted: Thu Jan 19, 2006 3:25 pm |
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Hi.
I am trying to make a pic16F639 talk to its internal Low Frequency front end via software SPI.
The 639 is identical to a 636 but has an MCP2030 chip in the same package, connected via RC1,2,3.
I have sample code from microchip for their demo board, which is in assembler. I am therefor trying to rewrite it in C. This is where I am running into trouble.
I hooked up a couple of unused IO's to an RS232 port in so I can monitor the what is happening internally, which tells me this
AFE[0] = 0xA0 -- SPI_READ[0] = 0x0000
AFE[1] = 0x00 -- SPI_READ[1] = 0x0000
AFE[2] = 0x00 -- SPI_READ[2] = 0x0000
AFE[3] = 0x00 -- SPI_READ[3] = 0x0000
AFE[4] = 0x00 -- SPI_READ[4] = 0x0000
AFE[5] = 0x10 -- SPI_READ[5] = 0x0000
AFE[6] = 0x4F -- SPI_READ[6] = 0x0000
the SPI_reads should return the AFE data, shifted left one bit. As you can see, it is not happening.. I think I have stared myself blind looking at this, so if anyone has any suggestions it would be most welcome 
I can upload the entire Assembly if needed, but it is rather long. These are the sections which I have failing :(
| Code: |
#define AFECS PORTC,1 ; Chip select output
#define SCK PORTC,2 ; SPI Clock Output
#define SDIO PORTC,3 ; Serial Data Input/Output
#define LFDATA PORTC,3 ; Low Frequency Data IN
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pin defines.
| Code: |
Set_up_AFE_Registers
bsf STATUS,RP0
movfw TRISC
andlw b'11000000' ; chuck, Setup SDIO,SCLK, and CS as outputs
movwf TRISC ;
bcf STATUS,RP0
; Register 0: 0000-0001 - 0 (parity)
;----------------------------------------------------
movlw WriteCommand+GeneralOptions+((AFEConfig0>>8)&0x01)
movwf SPIBufH
movlw AFEConfig0&0xFF
movwf SPIBufL
call ShiftOutSPIBuffer
; Verify Register 0
movlw ReadCommand+GeneralOptions
movwf SPIBufH
movlw 0x00
movwf SPIBufL
call ShiftOutSPIBuffer
call ShiftInSPIBuffer
movfw SPIBufL
xorlw AFEConfig0&0xFF
btfss STATUS,Z
retlw 0x01
; Register 1: 0000-0000 - 1 (parity)
;-------------------------------------------
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this repeats for each register, trying to save space here
| Code: | ;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
; Subroutine: ShiftOutSPIBuffer
;
; Description: This routine is used to shift data out of the microcontroller
; onto the SPI bus.
;
;Notes:
;1. This routine assumes 16-bit data is in SSPBufH and SSPBufL already.
;3. Control the ports as follows:
; Clear SCK/ALERT
; Clear chip select
;Loop
; Set or clear LFDATA/SDIO pin.
; Set SCK/ALERT
; Clear SCK/ALERT
; Goto Loop 16 times
; Set chip select
;Count00
;
;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ShiftOutSPIBuffer
movlw .16
movwf Count00
bcf SCK
bcf AFECS
ShiftOutLoop
rlf SPIBufL, f
rlf SPIBufH, f
btfss STATUS, C
bcf SDIO
btfsc STATUS, C
bsf SDIO
bsf SCK
bcf SCK
; CLRWDT
decfsz Count00, f
goto ShiftOutLoop
bsf AFECS
bcf AFECS
return
;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
; Subroutine: ShiftInSPIBuffer
;
; Description: This routine is used to shift data into the microcontroller
; from the SPI bus.
;
;Notes:
;1. This routine loads 16-bit data into the SSPBufH and SSPBufL registers.
;3. Control the ports as follows:
; Clear SCK/ALERT
; Clear chip select
;Loop
; Set SCK/ALERT
; Shift in the LFDATA/SDIO pin value.
; Clear SCK/ALERT
; Goto Loop 16 times
; Set chip select
;Count00
;
;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ShiftInSPIBuffer
movlw .16
movwf Count00
bsf STATUS,RP0
bsf TRISC,3 ;Set SDIO as an input
bcf STATUS,RP0
bcf SCK
bcf AFECS
ShiftInLoop
bsf SCK
btfss SDIO
bcf STATUS, C
btfsc SDIO
bsf STATUS, C
rlf SPIBufL, f
rlf SPIBufH, f
bcf SCK
; CLRWDT
decfsz Count00, f
goto ShiftInLoop
bsf AFECS
bcf SCK
bsf STATUS,RP0
bcf TRISC,3 ;Set SDIO as an output
bcf STATUS,RP0
return
;~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
So here is my C code. as my first attempt using fancier looking functions failed, I tried duplicating the assembly as much as possible, yet I am still failing :(
| Code: |
#use rs232(baud=9600,parity=N,xmit=PIN_C0,rcv=PIN_C4,bits=8)
#include "interupt.c" // file with the Interrupt Service Routines in it.
void main()
{
setup_timer_0(RTCC_INTERNAL|RTCC_DIV_256);
setup_timer_1(T1_DISABLED);
setup_comparator(NC_NC_NC_NC);
output_high(LF_CS);
// output_low(LF_ALERT);
// output_float(LF_ALERT);//
if( Set_Up_AFE_Registers()==0) {
output_low(PIN_A5);
}
// port_a_pullups(true);
// set_tris_a(0x01); // only pin 1 is input.used to wake up the processor from the low frequency front end.
// enable_interrupts(INT_EXT);
// enable_interrupts(GLOBAL);
printf("\n\r");
while(TRUE) {
sleep();
}//END WHILE
}// END MAIN
///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////
int Set_Up_AFE_Registers(void) {
int errorlevel=0;
int16 SPIREAD,TXDATA;
int i,address;
for(i=0;i<7;i++) {
address = SPI_WRITE_COMMAND | i; //WRITE AFE Registers
TXDATA = make16(address,AFE[i]);
TXDATA = TXDATA << 1;
TXDATA = parity16(TXDATA);
shift_out_SPI(TXDATA); //READ AFE Registers
address = SPI_READ_COMMAND | i; // Generate the SPI Read command
TXDATA = make16(address,0x00);
TXDATA = TXDATA << 1;
//TXDATA = parity16(TXDATA); .. seems the sample source code does not have parity on the read byte.
shift_out_SPI(TXDATA); // Send the read command
SPIREAD=shift_in_spi();// now clock the data back in
delay_ms(100);
printf("\r\nAFE[%d] = 0x%X -- ",i,AFE[i]);
printf("SPI_READ[%d] = 0x%LX",i,SPIREAD);
}
return errorlevel;
}
///////////////////////////////////////////////////////////////////////////////
void shift_out_SPI(int16 DATA) {
int i;
output_low(LF_ALERT);
output_low(LF_CS);
for(i=0;i<16;i++) {
if(bit_test(DATA,0)) {
output_high(LF_DATA);
}
else {
output_low(LF_DATA);
}
output_high(LF_ALERT);
output_low(LF_ALERT);
DATA = DATA >> 1;
}//end for
output_high(LF_CS);
//output_low(LF_CS);
output_float(LF_ALERT);
}//end function
///////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
int16 shift_in_spi(void){
int16 RETDATA;
int DATA[2];
int i;
//set_tris_c(SPI_READ_Direction);
//output_float(LF_DATA);
output_low(LF_ALERT);
output_low(LF_CS);
for(i=0;i<16;i++) {
shift_left(DATA,2,input(LF_DATA));
output_high(LF_ALERT);
output_low(LF_ALERT);
}
output_high(LF_CS);
output_low(LF_ALERT);
//set_tris_c(SPI_WRITE_Direction);
RETDATA=make16(DATA[1],DATA[0]);
return RETDATA;
} // end function
///////////////////////////////////////////////////////////////////////////////
//**************************************************************************//
int16 parity16(int16 DATA) {
// Add parity to the DATA to be send to the Low frequency front end.
// the parity is ODD, and only on the 8 data bits, which are located at'D' "CCCAAAADDDDDDDDP"
//the parity is added in the LSB position.
int i;
int count=0;
int16 ReturnData;
ReturnData= DATA;
for(i=0;i<8;i++) {
if(DATA& 0x0001) {
count++;
}
DATA=DATA>>1;
}
if(count%2 == 0){
ReturnData = (ReturnData | 0x0001); // the 0x0002 is because we check the lsb of the data, which is not in the right most position, as that is where the parity bit is.
}
return ReturnData;
}
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here is my pinout.h file
| Code: |
//RA_TRIS EQU B'00111111'
//RC_TRIS EQU B'00001110'
// ENDIF
// IFDEF P16F639
// _________
// Vdd | 1 20 | Vss
// S0 | 2 19 | S5/SlowFall
// S1 | 3 18 | S4/LFDint
// S2 | 4 17 | S3/SHIFT/RFEN
// DATA | 5 16 | LED1n 16F639
// LED2n | 6 15 | RC1/CSn
// RC3/LFDATA/SDIO | 7 14 | RC2/SCLK/Alert
// Vddt | 8 13 | Vsst
// LCZ | 9 12 | LCCOM
// LCY | 10 11 | LCX
// ---------
#define S0 PORTA,5 // S0 BUTTON INPUT
#define S1 PORTA,4 // S1 BUTTON INPUT
#define S2 PORTA,3 // S2 BUTTON INPUT
#define S3 PORTA,2 // S3 BUTTON INPUT
#define S4 PORTA,1 // S4 BUTTON INPUT
#define LFDint PORTA,1
#define S5 PORTA,0 // S5 BUTTON INPUT
#define RFEN PORTA,2 // RF ENABLE OUTPUT
#define RFENtris TRISA,2
#define SHIFT PORTA,2 // SHIFT BUTTON INPUT
#define LED PORTC,0 // LED output
#define AFECS PORTC,1 // Chip select output
#define SCK PORTC,2 // SPI Clock Output
#define SDIO PORTC,3 // Serial Data Input/Output
#define LFDATA PORTC,3 // Low Frequency Data IN
#define ValidLED PORTC,4 // LED output
#define RFOUT PORTC,5 // RF DATA OUTPUT
#define LF_CS PIN_C1
#define LF_ALERT PIN_C2
#define LF_DATA PIN_C3
#define SPI_CLK_DELAY 1
//Command(3 bits) address(4 bits) parity(1 bit) Odd Parity
#define SPI_CLAMP_ON 0x00
#define SPI_CLAMP_OFF 0x10
#define SPI_ENTER_SLEEP 0x20
#define SPI_AGC_PRESERVE_ON 0x30
#define SPI_AGC_PRESERVE_OFF 0x40
#define SPI_SOFT_RESET 0x50
#define SPI_READ_COMMAND 0x60
#define SPI_WRITE_COMMAND 0x70 // first 3 bits should be 111, followed by 4 address bits
// SPI Addresses
#define Config_Byte_0 0x00
#define Config_Byte_1 0x01
#define Config_Byte_2 0x02
#define Config_Byte_3 0x03
#define Config_Byte_4 0x04
#define Config_Byte_5 0x05
#define Colum_Parity 0x06
#define AFE_Status 0x07
#define STX 0x02
#define EOT 0x03
//#define TRUE 0x01
#define SPI_READ_Direction 0x08
#define SPI_WRITE_Direction 0x00
//******************************************************************************************
// Analogue Front End Configuration Table
//******************************************************************************************
// SGAFE Default Register Values
// Default Mode:Wake-up filter disabled. MODSIG= 0, Enable Ch-X only. 25% mod depth.
// Register 0: 1010-0001 - 0 (parity)
// #define AFEConfig0 0b10100000 //filter=enabled --> 2ms+2ms
#define AFEConfig0 0b10100000 //filter=enabled --> 2ms+2ms
// Register 1: 0000-0000 - 1 (parity)
#define AFEConfig1 0b00000000
// Register 2: 0000-0000 - 1 (parity)
#define AFEConfig2 0b00000000
// Register 3: 0000-0000 - 1 (parity)
#define AFEConfig3 0b00000000
// Register 4: 0000-0000 - 1 (parity)
#define AFEConfig4 0b00000000
// Register 5: 0001-0000 - 0 (parity)
#define AFEConfig5 0b00010000 // modulation depth, default = 75%
// Register 6: 0100-1111 - 0 (Parity) // column parity bits
#define AFEConfig6 0b01001111 // column parity at defalt mode (75%)
char AFE[7]={AFEConfig0,AFEConfig1,AFEConfig2,AFEConfig3,AFEConfig4,AFEConfig5,AFEConfig6};
#define AFECOLPARITY AFEConfig0 xor AFEConfig1 xor AFEConfig2 xor AFEConfig3 xor AFEConfig4 xor AFEConfig0
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Thu Jan 19, 2006 9:00 pm |
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I think you should just post one routine that's not working.
Post the assembly, and then the one C routine that doesn't work.
Explain how you know that it doesn't work. Show the
expected output and the actual output. |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Fri Jan 20, 2006 2:23 am |
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| I agree with PCM Programmer. I had a look at the code but didn't spot any obvious errors. It is a lot of code and I don't know what to look for so I stopped checking after 1 minute. If you want quick and usefull responses than give us a small compilable program that shows your problem. |
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Kasper
Joined: 14 Jan 2004
Posts: 88
Location: Aurora, Ontario, Canada
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| Posted: Fri Jan 20, 2006 12:08 pm |
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| PCM programmer wrote: | I think you should just post one routine that's not working.
Post the assembly, and then the one C routine that doesn't work.
Explain how you know that it doesn't work. Show the
expected output and the actual output. |
I expected this:
| Code: |
AFE[0] = 0xA0 -- SPI_READ[0] = 0x0000
AFE[1] = 0x00 -- SPI_READ[1] = 0x0000
AFE[2] = 0x00 -- SPI_READ[2] = 0x0000
AFE[3] = 0x00 -- SPI_READ[3] = 0x0000
AFE[4] = 0x00 -- SPI_READ[4] = 0x0000
AFE[5] = 0x10 -- SPI_READ[5] = 0x0000
AFE[6] = 0x4F -- SPI_READ[6] = 0x0000
|
as in I program in 0xA0 and read back 0x0000 ( the LSB << 1 contains the data)
I know I posted alot of code  but I am not sure if it is the write or the read routine which is not working. I verify by using a spare pin as a software RS232 port, printing out debug information..
I will work on it a bit more and see if I can spot where it goes wrong.
Thanks again for looking at it
Kasper |
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Kasper
Joined: 14 Jan 2004
Posts: 88
Location: Aurora, Ontario, Canada
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| Posted: Fri Jan 20, 2006 12:16 pm |
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| Code: |
ShiftOutSPIBuffer
movlw .16
movwf Count00
bcf SCK
bcf AFECS
ShiftOutLoop
rlf SPIBufL, f
rlf SPIBufH, f
btfss STATUS, C
bcf SDIO
btfsc STATUS, C
bsf SDIO
bsf SCK
bcf SCK
; CLRWDT
decfsz Count00, f
goto ShiftOutLoop
bsf AFECS
bcf AFECS
return
|
versus
| Code: | void shift_out_SPI(int16 DATA) {
int i;
output_low(LF_ALERT);
output_low(LF_CS);
for(i=0;i<16;i++) {
if(bit_test(DATA,0)) {
output_high(LF_DATA);
}
else {
output_low(LF_DATA);
}
output_high(LF_ALERT);
output_low(LF_ALERT);
DATA = DATA >> 1;
}//end for
output_high(LF_CS);
//output_low(LF_CS);
output_float(LF_ALERT);
}//end function |
Anything which stands out as being blatantly wrong?
Looking at the disassembly listing, wow is C ever creating alot more code than assembly
| Code: | 82: void shift_out_SPI(int16 DATA) {
83: int i;
84: output_low(LF_ALERT);
0D4 1683 BSF 0x3, 0x5
0D5 1107 BCF 0x7, 0x2
0D6 1283 BCF 0x3, 0x5
0D7 1107 BCF 0x7, 0x2
85: output_low(LF_CS);
0D8 1683 BSF 0x3, 0x5
0D9 1087 BCF 0x7, 0x1
0DA 1283 BCF 0x3, 0x5
0DB 1087 BCF 0x7, 0x1
86: for(i=0;i<16;i++) {
0DC 01BF CLRF 0x3f
0DD 083F MOVF 0x3f, W
0DE 3C0F SUBLW 0xf
0DF 1C03 BTFSS 0x3, 0
0E0 28F9 GOTO 0xf9
87: if(bit_test(DATA,0)) {
0E1 1C3D BTFSS 0x3d, 0
0E2 28E8 GOTO 0xe8
88: output_high(LF_DATA);
0E3 1683 BSF 0x3, 0x5
0E4 1187 BCF 0x7, 0x3
0E5 1283 BCF 0x3, 0x5
0E6 1587 BSF 0x7, 0x3
89: }
90: else {
0E7 28EC GOTO 0xec
91: output_low(LF_DATA);
0E8 1683 BSF 0x3, 0x5
0E9 1187 BCF 0x7, 0x3
0EA 1283 BCF 0x3, 0x5
0EB 1187 BCF 0x7, 0x3
92: }
93: output_high(LF_ALERT);
0EC 1683 BSF 0x3, 0x5
0ED 1107 BCF 0x7, 0x2
0EE 1283 BCF 0x3, 0x5
0EF 1507 BSF 0x7, 0x2
94: output_low(LF_ALERT);
0F0 1683 BSF 0x3, 0x5
0F1 1107 BCF 0x7, 0x2
0F2 1283 BCF 0x3, 0x5
0F3 1107 BCF 0x7, 0x2
95: DATA = DATA >> 1;
0F4 1003 BCF 0x3, 0
0F5 0CBE RRF 0x3e, F
0F6 0CBD RRF 0x3d, F
96: }//end for
0F7 0ABF INCF 0x3f, F
0F8 28DD GOTO 0xdd
97: output_high(LF_CS);
0F9 1683 BSF 0x3, 0x5
0FA 1087 BCF 0x7, 0x1
0FB 1283 BCF 0x3, 0x5
0FC 1487 BSF 0x7, 0x1
98: //output_low(LF_CS);
99: output_float(LF_ALERT);
0FD 1683 BSF 0x3, 0x5
0FE 1507 BSF 0x7, 0x2
100: }//end function
0FF 1283 BCF 0x3, 0x5
100 3400 RETLW 0 |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Jan 20, 2006 12:45 pm |
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Yes. The ASM code is shifting the 16-bit value to the left.
It shifts the MSB into the CY flag, and then tests it.
So it's shifting out the word "MSB first".
| Code: |
rlf SPIBufL, f
rlf SPIBufH, f
btfss STATUS, C
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But your C code is shifting it out "LSB first". You're doing a right-shift
and you're testing the LSB. You're doing the opposite of what the ASM
code is doing.
| Code: |
DATA = DATA >> 1;
if(bit_test(DATA,0))
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Kasper
Joined: 14 Jan 2004
Posts: 88
Location: Aurora, Ontario, Canada
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| Posted: Fri Jan 20, 2006 1:07 pm |
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| PCM programmer wrote: | Yes. The ASM code is shifting the 16-bit value to the left.
It shifts the MSB into the CY flag, and then tests it.
So it's shifting out the word "MSB first".
| Code: |
rlf SPIBufL, f
rlf SPIBufH, f
btfss STATUS, C
|
But your C code is shifting it out "LSB first". You're doing a right-shift
and you're testing the LSB. You're doing the opposite of what the ASM
code is doing.
| Code: |
DATA = DATA >> 1;
if(bit_test(DATA,0))
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Quoting a famous Cartoon Caracter...
DOH!
thanks PCM.. I am sure that will make one hell of a difference |
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