Datasheet

Interrupts ST7LITE20F2 ST7LITE25F2 ST7LITE29F2
50/170 DocID8349 Rev 7
External interrupt control register (EICR)
Read/Write
Reset Value: 0000 0000 (00h)
• Bit 7:6 = IS3[1:0] ei3 sensitivity
These bits define the interrupt sensitivity for ei3 (Port B0) according to Table 13:
Interrupt sensitivity bits.
• Bit 5:4 = IS2[1:0] ei2 sensitivity
These bits define the interrupt sensitivity for ei2 (Port B3) according to Table 13:
Interrupt sensitivity bits.
• Bit 3:2 = IS1[1:0] ei1 sensitivity
These bits define the interrupt sensitivity for ei1 (Port A7) according to Table 13:
Interrupt sensitivity bits.
• Bit 1:0 = IS0[1:0] ei0 sensitivity
These bits define the interrupt sensitivity for ei0 (Port A0) according to Table 13:
Interrupt sensitivity bits.
Note: These 8 bits can be written only when the I bit in the CC register is set.
Changing the sensitivity of a particular external interrupt clears this pending interrupt. This
can be used to clear unwanted pending interrupts. Refer to
External interrupt function on
page 64.
7 0
IS31 IS30 IS21 IS20 IS11 IS10 IS01 IS00
Table 13. Interrupt sensitivity bits
ISx1 ISx0 External interrupt sensitivity
0 0 Falling edge & low level
0 1 Rising edge only
1 0 Falling edge only
1 1 Rising and falling edge