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Functional Description
3
VMEbus Interface
The VMEbus interface is implemented with the CA91C042 Universe
ASIC. The Universe chip interfaces the 32/64-bit PCI local bus to the
VMEbus.
The Universe ASIC provides:
❏
The PCI-bus-to-VMEbus interface
❏
The VMEbus-to-PCI-bus interface
❏
The DMA controller functions of the local VMEbus
The Universe chip includes Universe Control and Status Registers
(UCSRs) for interprocessor communications. It can provide the VMEbus
system controller functions as well. For detailed programming
information, refer to the Universe User’s Manual and to the discussions in
the MVME2603/2604 Programmer's Reference Guide, listed in
Appendix
D, Related Documentation
.
ISA Super I/O Device (ISASIO)
The MVME2603/2604 uses a PC87308 ISASIO chip from National
Semiconductor to implement certain segments of the P2 and front-panel
I/O:
❏
Two asynchronous serial ports (COM1 and COM2) via P2 and
transition module
❏
Parallel port via P2 and transition module:
– Centronics printer port in MVME712M-compatible models
– IEEE1284 bidirectional parallel port in MVME761-compatible
models
❏
Floppy disk drive support via drive/power connector J4
❏
Keyboard and mouse interface via circular DIN connectors J6 and
J8