Bridge Link (CN4)

The Bridge Link connector allows devices that requires Legacy/ISA interrupts to inteface with the cpuModule. When ISA devices are installed in the system (via a PCI to ISA bridge card), the Bridge Link connector provides Legacy/ISA DMA request signals, as well as a serial interrupt signal which permits access to all available system interrupts.

Multiple devices may utilize the serial interrupt signal, SERIRQ, which is decoded on the cpuModule. Only one device may use the DMA request and grant signal pair.

Table 29 Bridge Link (CN4)

Pin

Signal

Function

 

 

 

1

GND

Ground

 

 

 

2

DMAREQ

Legacy/ISA DMA Request

 

 

 

3

SERIRQ

Serial Interrupt Request

 

 

 

4

DMAGNT

Legacy/ISA DMA Grant

 

 

 

Facing the connector pins, the pinout is:

31

SERIRQ

GND

DMAGNT

DMAREQ

42

46 CMX58886CX cpuModule

BDM-610000050 Rev A

Page 54
Image 54
IBM CMX58886CX user manual Bridge Link CN4