[35 pages of BDM docs] Useful, but some information is missing there.
Wait - I could swear the last time I looked at your reply, it said that you had "all the manuals" so this was irrelevant? I have the 1989 CPU32 manual, which has 35 pages of BDM info, including a couple timing diagrams
I acquired the full EVS kit, released by Motorola. It comes with the EVS board, the built-in DI debugger, and 10 manuals. But, have you ever read the CPU32 manual? Have you seen the manual itself says that some information is confidential? It means - not released to the public, only to companies affiliated with Motorola.
Years ago I was not thinking Motorola did this kind of strategy, but they did, and this also applies to the TPU32.
Examples I know are:
- Beckman, for the collaboration on spectrometers
- Ford Racing, for the collaboration on sport driving cars
In both of these two cases, I see a lot of customized 332 chip sold by Motorola to them, and as you know customization means, at least, custom microcode in the TPU's ROM. There is a public TPU assembly compiler, decent enough to make you write your own microcode and you can load it into the shared-ram between the CPU32 and the TPU at runtime, if you want it burned into the ROM you have to call Motorola. Beckman and Ford Racing did that. But the point is that who writes this microcode needs to know a lot of details for the TPU, some of these details are not covered in the public documentation. Anyway, the two persons I have recently met have confirmed what above, showing me manuals with a "confidential warning" on the first page. Besides it seems there was also a professional TPU compiler, more advanced than the one released to the public.
I was shocked, but now I am not surprised by finding this kind of strategy was also applied to the BDM.
Mainly you have a general description, but there are cases in the timing diagram, not covered by the manual, and not discussed in any public document, but they happen with a high probability and if you are not ready to handle they make the iteration unstable, and the BDM freezes. That is what I have experimented in person.
This makes sense since Motorola released this confidential information to their partners to do business with them, whereas the releasing a part of the documentation appeared a good way to attract and make new customers.
It's a common pattern in the strategy, it makes perfect sense.