— Block requests in
+ Interrupt request
- Poll ID bit 0
- Poll ID bit 1
- Poll ID bit 2
- Poll ID bit 3
- Poll ID bit 4
'request
(Fig. 2-18)
©
+ Clock interrupt
request
(Fig. 2-18)
Inverter
Inverter
Inverter
—Request in
bus bits 0O—15
4-to-16
decode
Gate
Inverter
+ Interrupt
level compare
(Fig. 2-18)
Inverter
Compare
Key:
@) = device interface with channel
(e) = off-page connection to anotherfigure
®
Inverter
IN = negative active signal
Figure 2-17. Poll mechanism—request and poll ID logic