Motorola MVME147 Installation And Use Manual page 95

Bits 4-5 These two bits conÞgure the VMEbus global time-out period.
VBTO1 is set to 1 and VBTO0 is cleared to 0 by SYSRESET.
VBTO1
0
0
1
1
The VMEbus global timer activates BERR* on the VMEbus.
Bit 6 Setting ARBTO to 1 enables the VMEbus arbitration timer. The
VMEbus arbitration timer activates BBSY* if it is not activated
within 410 µs after the MVME147 arbiter issues a bus grant. The
timer deactivates BBSY* as speciÞed in the VMEbus
speciÞcation. This causes the arbiter to arbitrate any pending
requests for the bus. This bit is set to 1 by SYSRESET.
Programming the VMEchip
VBTO0 Time-Out Period
0 102 microseconds
1 205 microseconds
0 410 microseconds
1 Timer disabled
4
4-45