Rolling my own computers in the 90s

[legacy]

a printer port and some C code 

my tap is usb-driven, I am going to use a modern linux/arm board, which has two usb ports, unfortunately no printer or usable gpio port

[joeqsmith]

I never picked up that that you were calling TAP had nothing to do with the industry standard TAP until now

witten in this topic, just a few posts above

yes, T.A.P. stands for a Test Access Port, for monitoring the internal memories of the CPU, and this pushes you in the direction of IEEE 1149.1 JTAG
because JTAG is needed for detailed testing and instrumentation of the CPU, for instance to capture or replay pipeline stalls, hazards, and exceptions.

but no, JTAG only has access to I/O pins, so, to implement real emulators and trace tools you must have a logic block with special access to internal data and control paths and things become boring and complex (e.g. see the JTAG-ADI bridge made by the OpenRisc team), while in my case the TAP is just  the interface to the debug processor, which talks to the host over a serial protocol (different from SWD)

I'm assuming  when you write BDM you actually mean Motorola's BDM standard.

if I do not tell you what an acronym is referring to, you can assume it's within the common standard, and in this case, BDM is Motorola BDM

What is what you call TAP doing that I can't achieve with the BDM?

my TAP is currently used in my Arise Softcore, which I have implemented in fpga. A software simulator (see the above post) is also existing as proof of concept.

Concerning my 332 board, I am going to build a bridge between my TAP and BDM, in this case the interface to MC68332 will be BDM, while the interface to my host PC, and all the software I have written to handle it, will be TAP

my Eprom emulator is also able to talk my TAP, as my TAP comes with a flexible protocol

I read it, saw serial debug port and TAP in one sentence and thought TAP.  Seems like if you want people to understand you are doing a unique serial debug test port for a digital device, don't copy an industry standard serial debug port for your name.   

When I was using the TAP, that CPU had no provision to do anything beyond control the I/O.  Most of what I see it used for is an easy way to test interconnects. 

Why would you waste time on the 332 is what I don't get.  Such an old, obsolete part.  Why not pick something at least of this decade to showcase your TAP? 

[legacy]

if you want people to understand you are doing a unique serial debug test port for a digital device, don't copy an industry standard serial debug port for your name.

renamed into "Otaku"

Why would you waste time on the 332 is what I don't get. 

obsolete means nothing, 332 is a good machine, it provides a good debug port, I like it, and that's all.

Why not pick something at least of this decade to showcase your TAP?

in first place because modern things come with jtag, or swi, and I do not like them
things like OpenRisc come with adi-jtag bridge, and again I do not like them

also I have no time and effort to support them

Otaku has been developed to help during the development of the Arise core
it's also useful to support my eprom emulator, and my VDU (video display unit)
it's exactly what I need as "swiss knife" to be used in fpga development, and it also helps in software debugging.

[joeqsmith]

if you want people to understand you are doing a unique serial debug test port for a digital device, don't copy an industry standard serial debug port for your name.

renamed into "Otaku"

That solves that.

[legacy]

if you want people to understand you are doing a unique serial debug test port for a digital device, don't copy an industry standard serial debug port for your name.

renamed into "Otaku"

That solves that.

the importance of being called "Otaku"

…. that sounds like dry sarcasm under the hood of its Etymology, especially when one got applied the term to unpleasant fans in caricature, as in modern Japanese slang, the term otaku is mostly equivalent to "geek" or "nerd", but in a more derogatory manner than used in the West, but it makes sense: even if it is more used for people with obsessive interests, commonly the anime and manga fandom, "Otaku" is also a Japanese term for another person's house or family, describing an open-roofed entrance hall or central court in an ancient house, while in modern buildings it is simply a room used for entry from the outside, sometimes referred to as a foyer or an entrance hall, in short it means "lobby room", and in my head sounds like "test point", as one doesn't need to be a Japanese-Sherlock Holmes to realize that … you can understand something about the house's owner just from the entrance, hence "tap", which stands for test access point (to my debug engine) has become the japanese name for "entrance point", and we are feeling fine


(kidding with Japanese and English, two languages that I wish I was able to master  )