Quatech RS-422/485, MPA-200/300 user manual Jumper Block Configurations, J4 Interrupt Configuration

4 JUMPER BLOCK CONFIGURATIONS

The MPA-200 utilizes seven user-selectable jumper blocks , that allow the user more flexibility when configuring the board. The following section explains the function of each of the jumper blocks on the MPA-200.

4.1J4 - Interrupt Configuration

J4 is a three pin jumper which determines whether or not a board’s interrupt is sharable. By selecting pins 1 & 2, the user has the ability to share an interrupt with other Quatech expansion cards. The MPA-200 will drive the interrupt onto the bus only when an interrupt occurs. Otherwise, the output is high impedance. If pins 2

&3 of J4 are selected, then interrupts abide by the IBM specification and cannot be shared. Table 5 summarizes the jumper block selections for J4. To maintain 100% ISA bus compatibility J7 should be set in No Interrupt Sharing mode.

Table 5 Jumper Block J4 Selections

Interrupt Function	Pins
Interrupt Sharing	1&2
No Interrupt Sharing	2&3

4.2J5 & J6 - Interrupt Level Selection

Jumper blocks J5 and J6 select the interrupt level that the MPA-200 utilizes. Inter- rupt levels IRQ2 - IRQ7 reside on J5, while interrupt levels IRQ10 - IRQ12 and IRQ14 - IRQ15 reside on J6. Table 6, and Table 7 summarize the jumper block selections for J5 and J6. The IRQ levels are also marked on the MPA-200 silk- screen for easy identification.

Table 6 Jumper block J5 selections.

Interrupt Level	Pins
IRQ2(9)	1&7
IRQ3	2&8
IRQ4	3&9
IRQ5	4&10
IRQ6	5&11
IRQ7	6&12

Table 7 Jumper block J6 selections.

Interrupt Level Pins

11 Quatech Inc., MPA-200/300 Manual