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Wed, 06 Jun 2007

Climbing evening.


This one was quite interesting, although I did not climb high on the walls, but spent most of the time at the bottom doing various boulderings, traverses and starts. There were couple of new interesting boulderings, but mostly it was the same as usual training.
I've found a training stream, which allows to quickly warm up, but it is too easy to cool down, and then feet starts aching when trying to push them in the climbing shoes (minus 3 sizes), so training must be quite aggressive with smaller rest times. But,frankly, it is unfair to climb at the bottom - you think that you do somthing serious and intresting, but as soon as arms start aching, you drop down and wait, while on the wall there is no way to move down, since after it you must start from the very beginning, which is not interesting, so you get the latest bits of power out of the body until either trace is completed, or you can not lift your arm at all.

/life :: Link / Comments (0)

Locking in SuperH.


Shame on me, I did not mention tas.b instruction, which does exactly what is needed for spinlock implementation - it reads a byte, specified in register, then sets a bit in the returned value, and writes it back. If value read is zero, special bit is set. All operations are performed with locked bus, so it is atomic.
I read description for that instruction many times, but failed to translate or understand. But, whatever it was, spilocks are pefectly valid on SH-4 family, so it would be possible to create SMP system, since I even found multiprocessor serial communication in 7750R, which allows to transfer data between multiple CPUs, where each receiver is addressed via unique ID.

/devel/sh :: Link / Comments (0)