C8051F336DK Silicon Laboratories Inc, C8051F336DK Datasheet - Page 89

• Manufacturer Part Number: C8051F336DK
• Description: DEV KIT FOR C8051F336
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051F336DK

• Contents: Evaluation Board, Power Supply, USB Cables, Adapter and Documentation
• Processor To Be Evaluated: C8051F33x
• Interface Type: USB, UART
• Operating Supply Voltage: 7 V to 15 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: C8051F336
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1430

15.3. External Interrupts /INT0 and /INT1
The /INT0 and /INT1 external interrupt sources are configurable as active high or low, edge or level sensi-
tive. The IN0PL (/INT0 Polarity) and IN1PL (/INT1 Polarity) bits in the IT01CF register select active high or
active low; the IT0 and IT1 bits in TCON
or edge sensitive. The table below lists the possible configurations.
/INT0 and /INT1 are assigned to Port pins as defined in the IT01CF register (see SFR Definition 15.5).
Note that /INT0 and /INT0 Port pin assignments are independent of any Crossbar assignments. /INT0 and
/INT1 will monitor their assigned Port pins without disturbing the peripheral that was assigned the Port pin
via the Crossbar. To assign a Port pin only to /INT0 and/or /INT1, configure the Crossbar to skip the
selected pin(s). This is accomplished by setting the associated bit in register XBR0 (see
“20.3. Priority Crossbar Decoder” on page 124
IE0 (TCON.1) and IE1 (TCON.3) serve as the interrupt-pending flags for the /INT0 and /INT1 external
interrupts, respectively. If an /INT0 or /INT1 external interrupt is configured as edge-sensitive, the corre-
sponding interrupt-pending flag is automatically cleared by the hardware when the CPU vectors to the ISR.
When configured as level sensitive, the interrupt-pending flag remains logic 1 while the input is active as
defined by the corresponding polarity bit (IN0PL or IN1PL); the flag remains logic 0 while the input is inac-
tive. The external interrupt source must hold the input active until the interrupt request is recognized. It
must then deactivate the interrupt request before execution of the ISR completes or another interrupt
request will be generated.
IT0
1
1
0
0
IN0PL
0
1
0
1
Active low, edge sensitive
Active high, edge sensitive
Active low, level sensitive
Active high, level sensitive
/INT0 Interrupt
(Section “24.1. Timer 0 and Timer 1” on page
Rev.1.0
for complete details on configuring the Crossbar).
IT1
1
0
0
1
IN1PL
C8051F336/7/8/9
0
1
0
1
Active high, edge sensitive
Active low, level sensitive
Active high, level sensitive
Active low, edge sensitive
/INT1 Interrupt
182) select level
Section
89