Structure Of External Interrupt Circuit 1; Figure 10.2-1 Block Diagram Of External Interrupt Circuit 1 - Fujitsu F2MC-8L Series Hardware Manual

10.2 Structure of External Interrupt Circuit 1

The external interrupt circuit 1 consists of three blocks, each with the same interrupt
functions.
Each block contains the following two elements:
• Edge detectors (0 to 2)
• External interrupt 1 control registers 1 and 2 (EIC1, EIC2)
Block Diagram of External Interrupt Circuit 1
Pin
P34/TO/INT0
Pin
P35/INT1
External interrupt 1
control register 1
(EIC1)
P36/INT2
Pin
External interrupt 2
control register 2
(EIC2)
Edge detector
If the edge polarity on the input signal to one of the external interrupt pins (INT0 to INT2)
matches the edge polarity specified for the pin in the EIC1 or EIC2 register (SL00 to SL21), the
edge detector sets the corresponding external interrupt request flag bit (EIR0 to EIR2) to "1".
External interrupt circuit 1 registers 1 and 2 (EIC1 and EIC2)
The EIC1 and EIC2 registers are used to select the edge, enable or disable interrupt requests,
and check interrupt requests.

Figure 10.2-1 Block Diagram of External Interrupt Circuit 1

Edge detector 1
01
00
1X
EIR1 SL11 SL10
10.2 Structure of External Interrupt Circuit 1
Edge detector 0
EIE1 EIR1 SL01
Edge detector 2
EIR2 SL21
01
00
1X
SL00 EIE0
Interrupt request
IRQ0
Interrupt request
IRQ1
1
0
1X
SL20 EIE2
Interrupt request
IRQ2
231