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MC68306 USER'S MANUAL
MOTOROLA
Table 2-4. Interrupt and Parallel Port Signal Summary
Signal Name
Mnemonic
Input/
Output
Three-State During
Bus Arbitration
Pullup Required
Interrupt Request Level 7, 4, 1
IRQ7, IRQ4, IRQ1
Input
—
(2)
Interrupt Request Level 6/Port B 7
IRQ6/PB7
I/O
—
(2)
Interrupt Request Level 5/Port B 6
IRQ5/PB6
I/O
—
(2)
Interrupt Request Level 3/Port B 5
IRQ3/PB5
I/O
—
(2)
Interrupt Request Level 2/Port B 4
IRQ2/PB4
I/O
—
(2)
Interrupt Acknowledge 7, 4, 1
IACK7, IACK4, IACK1
Output
—
Interrupt Acknowledge 6/Port B 7
IACK6
/PB3
I/O
—
(2)
Interrupt Acknowledge 5/Port B 6
IACK5
/PB2
I/O
—
(2)
Interrupt Acknowledge 3/Port B 5
IACK3
/PB1
I/O
—
(2)
Interrupt Acknowledge 2/Port B 4
IACK2
/PB0
I/O
—
(2)
Port A
PA7–PA0
I/O
—
(2)
NOTES:
2. Pullup or pulldown may be required, value depends on individual application.
Table 2-5. Clock and Mode Control Signal Summary
Signal Name
Mnemonic
Input/
Output
Three-State During
Bus Arbitration
Pullup Required
Crystal Oscillator or External
Clock
EXTAL
Input
—
Crystal Oscillator
XTAL
Output
—
System Clock
CLKOUT
Output
No
Address Mode
AMODE
Input
—