Section 16.5: Multiple bus initiators and Arbitration (Frame 7) [prev][home][next]

Fig. 16.5.2 shows several devices asserting their bus request lines, but only one is given control of the bus.

Fig. 16.5.2: Multiple bus initiators contend for the bus;
Both I/O controllers request the bus but only one gets control

The devices that attach to the bus and to the arbiter obey the protocol that they do not assert any control signals on the bus until their own bus grant line goes high. If they were to "cheat," the signals on the bus would be hopelessly confused and things would go haywire.