KX-NCP1290CJ (serv.man2) - Panasonic PBX Service Manual (repair manual). Page 7

7

Shows the external interrupt image.

External interrupt image

• nHALT signal polls using I/O port to achieve the consistency with the existing PBX.

However, in case the CPU(IC1) moves to the sleep mode while the system is halted, the unit returns from the sleep mode receiv-
ing the interrupt signal in CPU(IC1) when nHALT is released in accordance with its specification. 

• The nIRQ[0] interrupt of ASIC(IC2) should be set to the output, which is used as an interrupt output to the CPU (IC1); mainly

DPRAM communication interrupt. 
The LOS signal of PRI-IC(IC301) is the level output which goes to "H" when the line reference is lost.
Consequently, inputting the inverted LOS signal to the CPU (IC1) enables to generate a negative edge interrupt while the line ref-
erence is lost.
Also setting nIRQ4 terminal of CPU(IC1) to I/O port makes polling possible.
The unit is provided with interrupt processing in order to achieve the consistency with the existing PBX.
Polling with I/O port is disable because nRxMF signal of PRI-IC(IC301) is generated in a periodical frame timing.

• The unit should be kept open with a jumper unpopulated to avoid conflicting between output of nIRQ[0] of ASIC(IC2) and the sig-

nal.