My WAIT_n generator currently passing fully plustest.dsk's testbench is using the bad edge, something is wrong, it's a false positive. I know that NOP, HALT and IO_ACK/INT has to be good for this test to be valid. It's not the case here, so in fact my table of latencies is not the good one : running, but corrections are done on several bad instructions, some of them are even illogical, as this "RET cc" instruction where I had to hack the Z80 itself to reach a passing test, so something is wrong, and that thing is firstly the current WAIT_n generator clock edge (in comparison againts Z80's clock edge)
Have to change my approach, perhaps using invariant (table of full instruction chrono versus reality), validate instruction timing before trying validating IO_ACK interrupts. Write one table from plustest.dsk's testbench launched on WinAPE, and another table from original Z80 documentation, and deduce the a first theorical candidate table of latencies. I have to trust first in my instruction timing tables (and have to write them both completely...)
Prefixed instruction seems having only one M1 : Z80 doc show that a prefixed instruction take 4T more time.