NXP Semiconductors P89LPC9321 UM10310 - Manual (Page 27)

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User manual Rev. 2 — 1 November 2010 27 of 139
NXP Semiconductors
UM10310
P89LPC9321 User manual
If the external interrupt is level-triggered, the external source must hold the request active
until the requested interrupt is generated. If the external interrupt is still asserted when the
interrupt service routine is completed, another interrupt will be generated. It is not
necessary to clear the interrupt flag IEn when the interrupt is level sensitive, it simply
tracks the input pin level.
If an external interrupt has been programmed as level-triggered and is enabled when the
P89LPC9321 is put into Power-down mode or Idle mode, the interrupt occurrence will
cause the processor to wake-up and resume operation. Refer to
Section 5.3 “Power
reduction modes” for details. Note: the external interrupt must be programmed as
level-triggered to wake-up from Power-down mode.
3.2 External Interrupt pin glitch suppression
Most of the P89LPC9321 pins have glitch suppression circuits to reject short glitches
(please refer to the P89LPC9321 data sheet, Dynamic characteristics for glitch filter
specifications). However, pins SDA/INT0/P1.3 and SCL/T0/P1.2 do not have the glitch
suppression circuits. Therefore, INT1 has glitch suppression while INT0 does not.
Table 11. Summary of interrupts
Description Interrupt flag
bit(s) Vector
address Interrupt enable
bit(s) Interrupt
priority Arbitration
ranking Power-
down
wake-up
External interrupt 0 IE0 0003h EX0 (IEN0.0) IP0H.0, IP0.0 1 (highest) Yes
Timer 0 interrupt TF0 000Bh ET0 (IEN0.1) IP0H.1, IP0.1 4 No
External interrupt 1 IE1 0013h EX1 (IEN0.2) IP0H.2, IP0.2 7 Yes
Timer 1 interrupt TF1 001Bh ET1 (IEN0.3) IP0H.3, IP0.3 10 No
Serial port Tx and Rx TI and RI 0023h ES/ESR (IEN0.4) IP0H.4, IP0.4 13 No
Serial port Rx RI
Brownout detect BOIF 002Bh EBO (IEN0.5) IP0H.5, IP0.5 2 Yes
Watchdog timer/Real-time
clock WDOVF/RTCF 0053h EWDRT (IEN0.6) IP0H.6, IP0.6 3 Yes
I 2 C interrupt SI 0033h EI2C (IEN1.0) IP0H.0, IP0.0 5 No
KBI interrupt KBIF 003Bh EKBI (IEN1.1) IP0H.0, IP0.0 8 Yes
Comparators 1 and 2
interrupts CMF1/CMF2 0043h EC (IEN1.2) IP0H.0, IP0.0 11 Yes
SPI interrupt SPIF 004Bh ESPI (IEN1.3) IP1H.3, IP1.3 14 No
Capture/Compare Unit 005Bh ECCU(IEN1.4) IP1H.4, IP1.4 6 No
Serial port Tx TI 006Bh EST (IEN1.6) IP0H.0, IP0.0 12 No
Data EEPROM write
complete 0073h EAD (IEN1.7) IP1H.7, IP1.7 15 (lowest) No