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General Emulation => General Emulation => Topic started by: dink on May 08, 2019, 01:06:50 AM

Title: CPU tests
Post by: dink on May 08, 2019, 01:06:50 AM
Has anyone tested cpus like HD63701 or M6809, or know some docs - I need to know:
which registers survive a "hard reset" on these chips.  or if they are cleared, what are they cleared to.  We already know what's in mame's cpu emulation for reset, but, I'm looking for more information than mame can provide.

thanks,
- dink
Title: Re: CPU tests
Post by: Ryvius86 on May 08, 2019, 11:54:58 AM
http://datasheets.chipdb.org/Hitachi/63701/HD63701V0.pdf (http://datasheets.chipdb.org/Hitachi/63701/HD63701V0.pdf) - pg 638 has some information on resetting
http://www.gbgmv.se/dl/doc/md09/MC6809_DataSheet.pdf (http://www.gbgmv.se/dl/doc/md09/MC6809_DataSheet.pdf) - and same for pg 6

Hope this is what you're looking for.
Title: Re: CPU tests
Post by: dink on May 08, 2019, 07:21:33 PM
Ryvius86, I've seen this, and its unfortunately really vague.  I was hoping to find undocumented recon, such as someone loading each register, resetting and viewing the registers - on real HW of course. 

Let's take for example, the game Rompers on Namco System 1:
the game boots up, and loads stuff into the subcpu's ram & registers, then resets the chips.

If all of the registers of the hd63701 cpu are cleared on reset, boot fails.  I know the [somewhat related] hd6309 chip has a "v" register which survives a hw reset - it's even documented.  ..but.. info on the hd63701 about these things seems a little lacking :(

best regards,
- dink