UM10208_2
© NXP B.V. 2007. All rights reserved.
User manual
Rev. 02 — 1 June 2007
127 of 362
NXP Semiconductors
UM10208
Chapter 9: LPC2800 Interrupt controller
The specific interrupt service routine typically reads the status of the interrupting device,
and negates the request from the interrupting device, by means like reading data from the
device, writing data to the device, or simply disabling the device from requesting further
interrupts.
Finally the interrupt service routine needs to restore processor registers and context and
return to the interrupted process. A non-nested ISR also needs to re-enable interrupts,
while a nested routine needs to restore the value of the INT_PRIOMASK(0 or 1) register
that it saved in step 1 above. The interrupt controller does not need any other specific
service by the ISR.