In SX Microcontrollers, SX/B Compiler and SX-Key Tool, George Herzog wrote:

That sounds right.  If you don't enable the timers, they just sit and do nothing.  But, once they are enabled, someone has to go through all the choices of in the two configuration registers to get the right results.  In the case of PWM, the main goal is to time a duty cycle on an output pin, so the interrupt would be turned off.  

But, I still suspect that when you use the Watch Dog Timer, you may need to use one of the Multi-use Timers to run your ISR interrupts.  Since the 16-bit layout uses writes to two registers, it is nearly the same as an 8-bit Timer with pre-scaler set up of the RTCC.  You just have to include a few more steps in assembly language to provide the Timer with an interrupt value as the register is not Globally available.

In fact, now that I think of it, it could be best to do nothing to ISR and RTCC setup if you could find a way to have a multi-use Timer provide an alternative Watch Dog Timer.

I fear this may all be too complicated for most SX/B users as they may want Basic  to avoid all this low level stuff and just want a command that provides a function that works everytime and in every situation.

Sorry that I cannot help with an SX/B solution.  You  really don't have to reinstate the Timers two registers in entirety to have them be off line.  But you do have to go through MODE to reach the right register, then toggle the bit on the right Port.  Guenther's book has details on pages 267 and 268.  

 I do see that there is a lack of info about the original settings before you started messing with it.  It looks like one needs to get a factory fresh SX48 chip and read all these before they begin to use it.  I suspect going to PWM mode and then stopping the output is adequate. You can do the same thing is Software Timer mode, but also turn off any active interrupt bits.

In other words, some bits are Enable bits and some bits are informational flag bits.  One has to identify all the Enable bits to get things sorted out.  In this case, the names don't clearly identify which is what.

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