
Interrupt Control Unit
7-15
7.3.2
INT2 and INT3 Control Registers
(I2CON, Offset 3Ch, I3CON, Offset 3Eh)
(Master Mode)
The INT2 interrupt is assigned to interrupt type OEh. The INT3 interrupt is assigned to
interrupt type 0Fh.
The INT2 and INT3 pins can be configured as interrupt acknowledge pins INTA0 and INTA1
when cascade mode is implemented.
Figure 7-5
INT2 and INT3 Control Registers
The value of I2CON and I3CON at reset is 000Fh.
Bits 15–5: Reserved—Set to 0.
Bit 4: Level-Triggered Mode (LTM)—This bit determines whether the microcontroller
interprets an INT2 or INT3 interrupt request as edge- or level-sensitive. A 1 in this bit
configures INT2 or INT3 as an active High, level-sensitive interrupt. A 0 in this bit configures
INT2 or INT3 as a Low-to-High, edge-triggered interrupt. In either case, INT2 or INT3 must
remain High until they are acknowledged.
Bit 3: Mask (MSK)—This bit determines whether the INT2 or INT3 signal can cause an
interrupt. A 1 in this bit masks this interrupt source, preventing INT2 or INT3 from causing
an interrupt. A 0 in this bit enables INT2 or INT3 interrupts.
This bit is duplicated in the Interrupt Mask register. See the Interrupt Mask register in Section
7.3.10 on page 7-24.
Bits 2–0: Priority Level (PR2–PR0)—This field determines the priority of INT2 or INT3
relative to the other interrupt signals, as shown in Table 7-3 on page 7-18.
15
7
0
Reserved
PR2
PR1
PR0
MSK
LTM
Содержание Am186 ES
Страница 1: ...Am186 ES and Am188 ES User s Manual...
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Страница 12: ...Table of Contents xii...
Страница 22: ...Features and Performance 1 8...
Страница 60: ...System Overview 3 28...
Страница 84: ...Chip Select Unit 5 14...
Страница 132: ...Timer Control Unit 8 8...
Страница 166: ...Programmable I O Pins 11 6...
Страница 184: ...Register Summary A 18...