DS_1209F_004
73S1209F Data Sheet
Table 26: Control Bits for External Interrupts
Enable Bit Description
Flag Bit
IE0
Description
External interrupt 0 flag
EX0
EX1
EX2
EX3
EX4
EX5
EX6
Enable external interrupt 0
Enable external interrupt 1
Enable external interrupt 2
Enable external interrupt 3
Enable external interrupt 4
Enable external interrupt 5
Enable external interrupt 6
IE1
External interrupt 1 flag
External interrupt 2 flag
External interrupt 3 flag
External interrupt 4 flag
External interrupt 5 flag
External interrupt 6 flag
IEX2
IEX3
IEX4
IEX5
IEX6
1.7.3.4 Power Down Interrupt Logic
The 73S1209F contains special interrupt logic to allow INT0 to wake up the CPU from a power down
(CPU STOP) state. See the Power Control Modes section for details.
1.7.3.5 Interrupt Priority Level Structure
All interrupt sources are combined in groups, as shown in Table 27.
Table 27: Priority Level Groups
Group
0
1
2
3
4
5
External interrupt 0
Timer 0 interrupt
External interrupt 1
Timer 1 interrupt
Serial channel 0 interrupt
–
Serial channel 1 interrupt
–
–
–
–
–
External interrupt 2
External interrupt 3
External interrupt 4
External interrupt 5
External interrupt 6
Each group of interrupt sources can be programmed individually to one of four priority levels by setting or
clearing one bit in the special function register IP0 and one in IP1. If requests of the same priority level
are received simultaneously, an internal polling sequence as per Table 31 determines which request is
serviced first.
IEN enable bits must be set to permit any of these interrupts to occur. Likewise, each interrupt has its
own flag bit that is set by the interrupt hardware.
Interrupt Priority 0 Register (IP0): 0xA9 Å 0x00
Table 28: The IP0 Register
MSB
LSB
IP0.0
–
WDTS
IP0.5
IP0.4
IP0.3
IP0.2
IP0.1
Note: WDTS is not used for interrupt controls.
Rev. 1.2
37
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