saa-xc866 Infineon Technologies Corporation, saa-xc866 Datasheet - Page 52

• Manufacturer Part Number: saa-xc866
• Description: 8-bit Single-chip Microcontroller
• Manufacturer: Infineon Technologies Corporation

3.4.3
Each interrupt source, except for NMI, can be individually programmed to one of the four
possible priority levels. The NMI has the highest priority and supersedes all other
interrupts. Two pairs of interrupt priority registers (IP and IPH, IP1 and IPH1) are
available to program the priority level of each non-NMI interrupt vector.
A low-priority interrupt can be interrupted by a high-priority interrupt, but not by another
interrupt of the same or lower priority. Further, an interrupt of the highest priority cannot
be interrupted by any other interrupt source.
If two or more requests of different priority levels are received simultaneously, the
request of the highest priority is serviced first. If requests of the same priority are
received simultaneously, then an internal polling sequence determines which request is
serviced first. Thus, within each priority level, there is a second priority structure
determined by the polling sequence shown in
Table 17
Source
Non-Maskable Interrupt (NMI)
External Interrupt 0
Timer 0 Interrupt
External Interrupt 1
Timer 1 Interrupt
UART Interrupt
Timer 2,Fractional Divider, LIN Interrupts 6
ADC Interrupt
SSC Interrupt
External Interrupt 2
External Interrupt [6:3]
CCU6 Interrupt Node Pointer 0
CCU6 Interrupt Node Pointer 1
CCU6 Interrupt Node Pointer 2
CCU6 Interrupt Node Pointer 3
Data Sheet
Interrupt Priority
Priority Structure within Interrupt Level
48
Level
(highest)
1
2
3
4
5
7
8
9
10
11
12
13
14
Table
17.
Functional Description
SAA-XC866
V1.2, 2008-02