Strange address 0xFFFFFF00

[paul_met]

Faced with a strange address that goes beyond the Sega Saturn memory address space - 0xFFFFFF00. How to track read / write at this address? The Yabause debugger does not allow this. Maybe this address is a mirror of some other address?

 

[mrkotfw]

Clear bits 29~31. Yabause won't accept addresses with those bits set. Not sure why it's so strict.

 

[antime]

0xFFFFFE00-0xFFFFFFFF is the SH7095/SH7604 on-chip peripheral address range. 0xFFFFFF00 is the DVSR register of the division unit.

 

[paul_met]

So how to deal with this address? I need to track the value that is written to this address.

 

[antime]

You may have to modify the emulator.

 

[Ponut]

Well, this is not an address, per se. It is a register. So the fact it isn't in Yabause debugger is their fault.

To be more helpful, this register has read and write permission. So you could create a hack which, at your desired point, issues the command
STS DVSR,R#
and then check what's in the general purpose register you moved it to.

 

[paul_met]

The problem was solved by using the (inconvenient) Mednafen debugger.