Jameco Electronics 2000 ユーザーズマニュアル

ページ / 349
202
Rabbit 3000 Microprocessor
Figure 13-3.  Slave Port Handshaking and Interrupts
Figure 13-4 shows a sample connection of two slave Rabbits to a master Rabbit. The mas-
ter drives the slave reset line for both slaves and provides the main processor clock from 
its own clock. There is no requirement that the master and slave share a clock, but doing 
so makes it unnecessary to connect a crystal to the slaves. Each Rabbit in Figure 13-4 has 
to have RAM memory. The master must also have flash memory. However, the slaves do 
not need nonvolatile memory since the master can cold boot them over the slave port and 
download their program. In order for this to happen, the SMODE0 and SMODE1 pins 
must be properly configured as shown in Figure 13-4 to begin a cold boot process at the 
end of the slave reset.
Master writes SPD0R
Slave writes status register
Slave inbound interrupt requested
Visible in status register
Slave writes SPD0R
Master writes status register
/SLAVEATTN (PB7)
Visible in status register