HD64570 HITACHI [Hitachi Semiconductor], HD64570 Datasheet - Page 51

• Manufacturer Part Number: HD64570
• Description: Serial Communications Adaptor
• Manufacturer: HITACHI [Hitachi Semiconductor]

1.7.12
The SCA has a built-in bus arbiter for arbitrating the bus between the on-chip DMAC and an
external bus master device. This bus arbiter provides an easy way to design a multi-channel
system using two or more SCA chip (figure 1.23). The circuit shown here merely represents the
concept of the multi-channel system. In practice, the user system should be designed while
referring to the bus arbitration sequence (figure 3.6).
MPU
BUSACK BUSREQ
BUSACK
BUSREQ BUSY
Bus Arbiter
SCA
HD64180,
etc.
Figure 1.23 Daisy-Chained Multi-Channel System (example)
BEO
Glue logic
BUSACK
BUSREQ BUSY
SCA
BEO
BUSACK
BUSREQ BUSY
SCA
BEO
Rev. 0, 07/98, page 35 of 453
BUSACK
BUSREQ BUSY
SCA
BEO
+ 5 V