P2 Taqoz V2.8 for 25MHz Crystal of Kiss with SD-Card @921600 baud
Christof Eb.
Posts: 1,214
So, if you want to run P2 Taqoz V2.8 for 25MHz Crystal of Kiss board with SD-Card @921600 baud:
To be aligned with Bobs great docu https://forums.parallax.com/discussion/173302/taqoz-reloaded-v2-8-word-glossary/p1
this is for V2.8 which is found https://sourceforge.net/projects/tachyon-forth/files/TAQOZ/binaries/ Taqoz.zip
Included is the original ZIP of V2.8 and also a ZIP, which contains a patched bootfile for 25MHz crystal.
Patching was done with the following steps:
R4 pulldown removed. Original bootfile _BOOT_P2.BIX copied to a sd card.
Due to the 25MHz cristal, the clock frequency is 250MHz instead of 200MHz and baud rate is 1152000 ( = 921600 *25/20 ) .
Terminal program PuTTY can switch a prop plug to this unusual baudrate. Now you can contact Taqoz on P2. :-)
There is in the DAT section of the source "taqoz.spin2":
XIDIV = 1 ' crystal/osc input divider'
VCODIV = 1
CLKMUL = CPUHZ/(XIN/XIDIV)
CLKCFG = 1<<24+(XIDIV-1)<<18+(CLKMUL-1)<<8+((VCODIV-2)&$0F)<<4+PF15
Original value of CLKCFG is : $0100_09F8
This constant is located at 24decimal.
To get a system running at 200 MHz with crystal 25MHz and with baud rate 921600:
$0100_07F8 24 !
200.000.000 20 !
25.000.000 16 !
BACKUP BIX
After booting the baud rate is 921600 as intended and the clock frequency is 200MHz.
Comments
Has anyone been able to modify TAQOZ_V2_8_2104/taqoz.spin2 and compile ? I get an error from line 235
/home/colin/flexprop/bin/flexspin -2 -l --tabs=4 -D_BAUD=921600 -O1 -I "/home/colin/flexprop/include" "/home/colin/TAQOZ_V2_8_2104/taqoz.spin2"
Propeller Spin/PASM Compiler 'FlexSpin' (c) 2011-2021 Total Spectrum Software Inc.
Version 5.9.1-beta-HEAD-v5.4.3-419-g359148b7 Compiled on: Aug 30 2021
/home/colin/TAQOZ_V2_8_2104/taqoz.spin2:235: error: syntax error, unexpected number
taqoz.spin2
child process exited abnormally
Finished at Tue Sep 14 13:14:25 2021
Hi,
I had tried this approach of recompiling from source first. After I had some error messages I tried to patch like described in the first post. At the moment I am happy with this. One problem of Taqoz sourceforge is, that you don't know, which files have been used. The source files are not consistent with the bix. For example the actual output pins for VGA do not fit to the lst....
got rid of the compile errors,
patch and spin2 attached,
testing, running nicely at 115200 baud, so far, so good,
compiles, runs, flash and reboot from flash using flexprop