Signal Description
2-4
MC68307 USER’S MANUAL
MOTOROLA
Table 2-4. Interrupt Port Signal Summary
Signal Name
Mnemonic
Input/
Output
Three-State During
Bus Arbitration
Pullup Resistor
Required
Interrupt Request Level 7
IRQ7
Input
—
(1)
Latched Interrupt 1
INT1/PB8
Input (2)
—
(1)
Latched Interrupt 2
INT2/PB9
Input (2)
—
(1)
Latched Interrupt 3
INT3/PB10
Input (2)
—
(1)
Latched Interrupt 4
INT4/PB11
Input (2)
—
(1)
Latched Interrupt 5
INT5/PB12
Input (2)
—
(1)
Latched Interrupt 6
INT6/PB13
Input (2)
—
(1)
Latched Interrupt 7
INT7/PB14
Input (2)
—
(1)
Latched Interrupt 8
INT8/PB15
Input (2)
—
(1)
NOTES:
1. Pullup or pulldown may be required (value depends on individual application).
2. These signals have dual functions as port B I/O lines. Their function is programmed in the port B control register.
Table 2-5. Clock and Mode Control Signal Summary
Signal Name
Mnemonic
Input/
Output
Three-State During
Bus Arbitration
Pullup Resistor
Required
Crystal Oscillator or External Clock
EXTAL
Input
—
Crystal Oscillator
XTAL
Output
—
System Clock
CLKOUT
Output
No
—
Initial Bus Width for CS0
BUSW0
Input
—
Power-On Reset
RSTIN
Input
—
(1)
NOTE:
1. Pullup may be required (value depends on individual application). This pin must not be left oating.
Table 2-6. Serial Module Signal Summary
Signal Name
Mnemonic
Input/
Output
Three-State During
Bus Arbitration
Pullup Resistor
Required
UART Transmitter Serial Data
TxD/PB2
Output (1)
No
—
UART Receiver Serial Data
RxD/PB3
Input (1)
—
UART Request-to-Send
RTSA/PB4
Output (1)
No
—
UART Clear-to-Send
CTSA/PB5
Input (1)
—
(2)
NOTES:
1. These signals have dual functions as port B I/O lines. Their function is programmed in the port B control register.
2. Pullup may be required (value depends on individual application). If used as CTSA this pin must not be left oating.
Table 2-7. JTAG Signal Summary
Signal Name
Mnemonic
Input/
Output
Three-State During
Bus Arbitration
Pullup Resistor
Required
Test Clock
TCK
Input
—
Test Data Input
TDI
Input
—
Test Data Output
TDO
Output
—
Test Mode Select
TMS
Input
—