MVME51005E Single Board Computer Installation and Use (6806800A38B)
4 Functional Description
42
VMEbus Interface
The VMEbus interface is provided by the Universe II ASIC. Refer to the
Universe II User’s
Manual,
as listed in
Appendix D, Related Documentation
, for additional information.
Asynchronous Communications
The MVME5100 provides dual asynchronous debug ports. The serial signals COM1 and COM2
are routed through appropriate EIA-232 drivers and receivers to an RJ45 connector on the front
panel (COM1) and an on-board connector (COM2). The external signals are ESD protected.
Real-Time Clock & NVRAM & Watchdog Timer
The MVME5100’s design incorporates 32KB of non-volatile static RAM, along with a real-time
clock and a watchdog function an integrated device. Refer to the
M48T37V CMOS 32Kx8
Timekeeper SRAM Data Sheet
, as referenced in
Appendix D, Related Documentation
for
additional programming and engineering information.
Timers
Timers and counters on the MVME5100 are provided by the board’s hardware (Hawk ASIC).
There are four 32-bit timers on the board that may be used for system timing or to generate
periodic interrupts.
Interrupt Routing
Legacy interrupt assignment for the PCI/ISA Bridge is maintained to ensure software
compatibility between the MVME5100 and the MVME2700 while in SBC mode.
This is accomplished by using the corresponding on-board IPMC712 or IPMC761 connector to
route the PCI/ISA Bridge interrupt signal to the external interrupt 0 of the Hawk ASIC (MPIC).
Note
The SCSI device on either the IPMC712 or IPMC761 uses the standard INTA# pin J11-
04 of PMC Slot 1.
IDSEL Routing
Legacy IDSEL assignment for the PCI/ISA Bridge is also maintained to ensure software
compatibility between MVME5100 and the MVME2700 while in SBC mode (also called 761 or
IPMC mode).
This is accomplished by using either the on-board IPMC712 or IPMC761 connector to route
IDSEL (AD11) to the PCI/ISA Bridge on the IPMC712 or IPMC761.
Note
The SCSI device on the IPMC712 and IPMC761 uses the standard IDSEL pin J12-25
connected to AD16.
When a standard PMC card (not the IPMC712 or IPMC761) is plugged into slot 1, its IDSEL
assignment corresponds to the standard IDSEL pin J12-25 and shall be connected to AD16.