Strange SX-48 Behavior

RS_Jim

I have been running the TX_HEX2 subroutine that is in the example programs and had it work successfully. Now all of a sudden it prints $E for the second digit regardless of what the input is.· Watching it in single step mode, what is happening, no matter what the character stored in the tmpB2 register the W register is getting loaded with $FE.· I put in a \ Mov W,#0 command prior to loading the tmpB2 but to no avail.· It loads $FE in the W regester.
I tried moving the Subroutine code to another page, again the same problem.
Anyone have any ideas?
Jim
·

Peter Verkaik

Have you also checked it with SxSim?
Can you post the code?

regards peter

JonnyMac

I think that's probably one of my subroutines -- and you may be using an older version of it. Since TX_HEX2 uses TX_BYTE you need to make sure that there is no negative interaction. This is the code that I am presently using for both routines:

' Use: TX_BYTE aByte

SUB TX_BYTE
  SEROUT TX, Baud, __PARAM1
  ENDSUB

' -------------------------------------------------------------------------

' Use: TX_HEX2 byteVal
' -- transmit byte in HEX2 format

SUB TX_HEX2
  tmpB1 = __PARAM1
  
  tmpB2 = tmpB1 & $F0                           ' isolate high nib
  SWAP tmpB2                                    ' move for READ
  READ Hex_Digits + tmpB2, tmpB2                ' convert to ASCII
  TX_BYTE tmpB2
  tmpB1 = tmpB1 & $0F                           ' isolate low nib
  READ Hex_Digits + tmpB1, tmpB1
  TX_BYTE tmpB1
  ENDSUB

' -------------------------------------------------------------------------
' User Data
' -------------------------------------------------------------------------

Hex_Digits:
  DATA  "0123456789ABCDEF"

Post Edited (JonnyMac) : 8/11/2008 5:25:30 PM GMT

RS_Jim

Jonny Mac,
Thanks for the insite. I am using an interupt driven version of your code for TX and RX. The TX-HEX2 sub I think I used from the help file on SXB
I will lookinto it. Thanks
Jim

JonnyMac

You might want to use the attached program as reference. Since I do so many SX projects with serial comms I am constantly refining my code -- what's attached is the current state of my efforts and will move easily between the SX28 and SX48. It's important to know that in SX/B the global vars are in BANK $00 for the SX18/20/28 and in BANK $10 for the SX48/52. As this can affect assembly segments (e.g., ISR-driven UARTs) this program has a constant called __DEFAULT that you must change based on the processor you're using. In SX/B 2.0 the __DEFAULT constant is built in, so when that is released you'll need to delete that CON definition.

[noparse][[/noparse]Edit] Added BIN8 and DEC3 output routines
[noparse][[/noparse]Edit] Improved and updated -- see post below

Post Edited (JonnyMac) : 8/19/2008 5:19:44 AM GMT

RS_Jim

Thanks Jonny,

That solves all sorts of problems! Now I have to recalculate the baud rate constants for a 20 MHz xtal, but I believe I have downloaded a calculator that does all that for virtual periferals. I was going to put the __default in an ifdef statement but it did not want to compile right so will figure that out later.

Jim

JonnyMac

No, no, no! You don't have to recalculate anything. The rate parameter of of INTERRUPT takes care of all the gnarly work for the ISR (setting the OPTION bits and RETURNINT value) -- so don't screw it up with unnecessary experimenting! All you have to do is change the FREQ and OSC settings. There are constants defined for common baud rates.

I didn't have any trouble with a conditional compilation setup for the __DEFAULT constant. See attached.

Post Edited (JonnyMac) : 8/19/2008 5:23:01 AM GMT

RS_Jim

jonny Mac,

leave it to me to do things the hard way.· I was having trouble trying to determine how to set the interupt rate until I figured out that it was the recipricol of the interupt timing. The problem I had with the if def was failing to write it with the ' in front of the { . When I looked at your example I saw the error of my ways.· You might emphasise the importance of the '{ } structure in an example in the help file.· One of the difficulties I have in reading the help file is that the highlighted segments sometimes mask important features like a comma after a command statement or a ' infront of something.

Thanks again for all you do!

Jim