T89C5115 ATMEL Corporation, T89C5115 Datasheet - Page 85

• Manufacturer Part Number: T89C5115
• Description: Low Pin Count 8-bit MCU with A/D Converter and 16-Kbytes of Flash Memory
• Manufacturer: ATMEL Corporation

4128A–8051–04/02
Table 60. Priority Level Bit Values
A low-priority interrupt can be interrupted by a high priority interrupt but not by another
low-priority interrupt. A high-priority interrupt cannot be interrupted by any other interrupt
source.
If two interrupt requests of different priority levels are received simultaneously, the
request of the higher priority level is serviced. If interrupt requests of the same priority
level are received simultaneously, an internal polling sequence determines which
request is serviced. Thus within each priority level there is a second priority structure
determined by the polling sequence, see Table 61.
Table 61. Interrupt Priority Within Level
external interrupt (INT0)
external interrupt (INT1)
PCA (CF or CCFn)
Interrupt Name
UART (RI or TI)
Timer0 (TF0)
Timer1 (TF1)
Timer2 (TF2)
ADC (ADCI)
IPH.x
0
0
1
1
Interrupt Address Vector
IPL.x
0003h
000Bh
0013h
001Bh
0033h
0023h
002Bh
0043h
0
1
0
1
Interrupt Level Priority
Priority Number
T89C5115
3 (Highest)
0 (Lowest)
1
2
1
2
3
4
5
6
7
8
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