MC68HC901 Datasheet, PDF (63/73 Pages) Motorola, Inc – Multi-Function Peripheral

Electrical Characteristics
CLK
4
IACK
DS
IEI
IEO
D0 - D7
DTACK
19
(NOTE 1)
20
18
A
B
(NOTE 2)
18
6
17
9
7
NOTES:
1. IEO only goes low if no acknowledgable interrupt is pending. If IEO goes low, DTACK and
the data bus remain in the high-impedance state.
2. DTACK will go low at A if specification number 14 is met. Otherwise, DTACK will go
low at B .
Figure 8-6. Interrupt Acknowledge Cycle (IEI High)
I7 - I0
IRQ
FIGURE - INTERRUPT ACKNOWLEDGE CYCLE (IEI High) TIMING
25 _{MC68HC901UM / AD}
36
NOTE: Active edge is assumed to be the rising edge.
Figure 8-7. Interrupt Timing
CLK
I7 - I0
FIGURE - INTERRUPT TIMING
MC68HC901UM / AD
27
Figure 8-8. Port Timing
FIGURE - PORT TIMING
MC68HC901UM / AD
8-10
MC68HC901 USER’S MANUAL
MOTOROLA