7.1.2
Block Diagram
Figure 7-1 shows a block diagram of the bus controller.
External bus control signals
WAIT
Legend:
ABWCR : Bus width control register
ASTCR
BCRH
BCRL
WCRH
WCRL
142
controller
: Access state control register
: Bus control register H
: Bus control register L
: Wait control register H
: Wait control register L
Figure 7-1 Block Diagram of Bus Controller
Area decoder
ABWCR
ASTCR
BCRH
BCRL
Bus
controller
Wait
WCRH
WCRL
CPU bus request signal
DTC bus request signal
Bus arbiter
CPU bus acknowledge signal
DTC bus acknowledge signal
Internal
address bus
Internal control
signals
Bus mode signal