user manual

Hardware Preparation
2-9
2
3. Header J2 is used to select the power source used to back up the SRAM on the
MVME177 when the backup battery is installed.
!
Caution
Do not remove all jumpers from J2. This may
disable the SRAM.
If you remove the battery, you must install jumpers on J2 between pins 2 and 4,
as shown for Backup Power Disabled.
4. The MVME177 can be the VMEbus system controller. The system controller
function is enabled, disabled, or conÞgured for automatic select by jumpers on
header J6. If set for AUTO SCON, the MVME177 determines if it is the system
controller by its position on the bus. If the MVME177 is in the Þrst slot from the
left, it conÞgures itself as the system controller. When the MVME177 is system
controller, the
SCON LED is turned on. The VMEchip2 may be conÞgured as a
system controller when J6 is jumpered as shown.
!
Caution
Do not jumper J6 to Auto System Controller. At
this time, this feature is not functioning
properly. Set up jumpers on J6 only as
System Controller or Not System Controller.
Note
AUTO SCON only works with a non-active
backplane.
5. The thermal sensing pins, THERM1 and THERM2, are connected to an internal
thermal resistor and provide information about the average temperature of the
processor. Refer to the M68000 Microprocessors UserÕs Manual for additional
information on the use of these pins.
6. The FLASH jumper, J8, is used to select the Flash memory and EPROM
conÞguration on the MVME177. If the board is conÞgured for 1MB EPROM and
2MB Flash memory, the VMEchip2 GPIO bits can be programmed to select the
Þrst or second 2MB of Flash. See Chapter 4 for more information on Flash
memory. You can also use the 177Bug SFLASH command to map the Flash
memory.
7. Serial port 4 can be conÞgured to use clock signals provided by the RTXC4 and
TRXC4 signal lines. Headers J9 and J10 on the MVME177 conÞgure serial port 4
to drive or receive RTXC4 and TRXC4, respectively. Both jumpers should be set
the same way. Factory conÞguration is with port 4 set to receive both signals.
The remaining conÞguration of the clock lines is accomplished using the Serial
Port 4 Clock ConÞguration Select header on the MVME712M transition board.
Refer to the MVME712M Transition Module and P2 Adapter Board UserÕs Manual
for conÞguration of that header.
MVME177 Header Notes: (Continued)