Only reads one byte, but good enough.. to get things done.
Code should actually work for low and high speed, but have only tested
high speed on writes so far.
Having issue where reads can fail at times. Esp with long strings of
'0'.. Perhaps operating at high speed would improve matters..
Although I'm also realizing maybe I'm not waiting for the device to reset
and reload HSI trim factory value, need to check that..
The new assembly file/function does everything needed so can start cutting
out inline assembly from swim_out function.
Swim code needs to run at 48Mhz. Realizing this is pretty vital to having
enough time to handle high speed. And timing of artificial pull-up
requires high trimmability..
Able to enter active mode and Write on the fly.
Simple test to toggle LED on STM8 GPIO works!
Still quite far from ideal setup. Some things needed:
-defines for ACK/NAK/NO_RESP in dictionary to report inteligbly to lua
-move test SWIM code into separate lua script
-define STM8-CIC registers for easier calling from lua
-entering active mode is too board dependent, need to use swim_base
-Need to make better use of device timers for entering active mode
-arm assembly is quite a mess, unaware of calling convention when writting
-stopping more than just r0-4, r5+ need to be restored if used
-thinking I'd like a full out assmebly file that gets compiled separately
-nothing is done to support SWIM with AVR
-hacking lack of powerful enough pullup on SWIM pin
not much that can be done to get around this...
don't want to add resistors to programmer for every pin I 'might' use
don't want to add resistors to each board that's made
-seems to work well enough, but reads will prob prove challenging
-currently only running at slow speed with ton of NOPs
AVR not yet working, performing low level SWIM operations will require
decent amount of core specific code due to differences in pin driver
styles, timers, cycles per instruction, etc. The fact that SWIM pin
changes based on the board ADDR0, DATA0, EXP0, etc multiplies this low
level code... Thinking about executing SWIM low level drivers from SRAM.
Initialization could include loading these routines to SRAM.
For now just focusing on supporting SWIM on STM cores for SNES boards.
Paul Molloy