Specifications

Chapter 2 Hardware Installation 15
the bit is 1, then no interrupt is generated. The following table shows
the correspondence between the status register bit which gets set to 0
and the port assigned to generate an interrupt.
Interrupt Status Register S2
Bit Function
0 Port 1
1 Port 2
2 Port 3
3 Port 4
4 Not Used
5 Not Used
6 Not Used
7 Not Used
A user may change the interrupt status registers' address using the DIP
switch S2. Please note that the address decoder will occupy a
continuous, 16-byte string of registers starting from the switch setting.
For example, if you set the switch to 210H, then the contents of the
registers from 210H to 21FH will all be decoded. The various DIP
switch settings (S2) and their corresponding interrupt status register
addresses are shown in the table on the following page. The figure
below shows the default setting of switch S2.