nmk/ddealer.cpp: replace MCU simulation in ddealer with emulated NMK-110 MCU (also tdragon1, hachamf, hachamfa in nmk16.cpp) [Sergio Galiano, Recreativos Piscis, David Haywood, hammy] #11584
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…aliano, Recreativos Piscis, David Haywood, hammy]
| void ddealer_state::mcu_port6_w(u8 data) | ||
| { | ||
| // the actual mechanism is a little more complex, but these are written at the | ||
| // start and end of the take / release bus function |
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Can you elaborate a bit? Connected to bus request I presume?
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the notes I was sent
writes 0x03: 0011 (important thing is bit 3 is zero, asking for bus request)
reads bit 2, until it's zero (receiving bus grant signal from 68k)
writes 0x01: 0001 (important thing here is bit 1 is zero, sending bus grant acknowledge signal to 68k)
writes 0x08: 1000 (important thing here is bit 0 is zero, enabling the memory access logic in the pcb)
wirites 0x09: 1001 (important thing here is bit 0 is one, disabling the memory access logic in the pcb)
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@angelosa yes, it's 68k bus arbitration lines. Device is hooked to the main CPU in this way:
- Bus request line is bit 3 of Port 6 and configured as output
- Bus grant line is bit 2 of the Port 6 and it's configured as input
- Bus grant acknowledge line is bit 1 of the Port 6 and it's configured as output
- Also there is another pin that enables the pcb logic to access the bus after all of above it's done, that is the bit 0 of the Port 6, configured as output, too
angelosa
changed the title
…multipurpose MCU, as it has multiple program paths depending on a port.
mamehaze
changed the title
src/mame/nmk/ddealer.cpp
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| if (data == 0x08) | ||
| { | ||
| logerror("%s: mcu_port6_w 68k bus taken, 68k stopped (data %02x)\n", machine().describe_context(), data); | ||
| m_maincpu->set_input_line(INPUT_LINE_HALT, ASSERT_LINE); | ||
| } | ||
| else if (data == 0xb) | ||
| { | ||
| logerror("%s: mcu_port6_w 68k bus returned, 68k started (data %02x)\n", machine().describe_context(), data); | ||
| m_maincpu->set_input_line(INPUT_LINE_HALT, CLEAR_LINE); | ||
| } | ||
| else | ||
| { | ||
| logerror("%s: mcu_port6_w 68k bus access (data %02x)\n", machine().describe_context(), data); | ||
| } |
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Please replace these with LOG – having the logging always enabled here is a bit heavy for something attached to bus arbitration.
Also, @galibert can you check if this is this the right way to be doing this? I want to be sure it’s up-to-date for the new, interruptible 68k.
src/mame/nmk/ddealer.cpp
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| u8 ddealer_state::mcu_port6_r() | ||
| { | ||
| // again this is simplified for now | ||
| m_bus_status ^= 0x04; | ||
| return m_bus_status; | ||
| } |
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Once again @galibert is there a clean way to do this? Magic side effects of reading ports that aren’t strobed is a fairly obvious hack.
…if we use the 110
…ll taken care of by the MCUs
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@angelosa I don't believe any of your code remains in ddealer.cpp now (it was mostly the simulation?) From what I can see I recognize all the functional code in there as my own, including the weird (probably needs more research) video implementation. I propose to relicense it as BSD-3-Clause. |
I definitely remember spotting palette among other things from the initial Tomasz stub. It's otherwise fine to downgrade to BSD to me. |
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For the record, OG said he'd take a look at this once he figures out how the bus request stuff should be done. |
nmk/ddealer.cpp: replace MCU simulation in ddealer with emulated NMK-110 MCU [Sergio Galiano, Recreativos Piscis, David Haywood, hammy]
nmk/nmk16.cpp: replace MCU simulation in tdragon1 with emulated NMK-110 MCU [Sergio Galiano, Recreativos Piscis, David Haywood, hammy]
nmk/nmk16.cpp: replace MCU simulation in hachamf, hachamfa with emulated NMK-113 MCU [Sergio Galiano, Recreativos Piscis, David Haywood, hammy]