Connect Tech CTIM-00043 Single Interrupt Mode, Dual Interrupt Mode, Shared Interrupt Mode

CANpro/104 User Manual

Single Interrupt Mode

This mode routes the interrupt signal from both SJA1000 CAN controllers to one PC/104 Bus Interrupt signal. This mode is set up by installing Jumper J1/J2 Position “S” (either the CAN-0 or the CAN-1 “S” position can be used). When this jumper is installed, the Interrupt signal occurs on the “CAN-0 row” of J1 and J2 (red box).

Dual Interrupt Mode

This mode routes the interrupt signal from the CAN-0 SJA1000 CAN controller to the CAN-0 PC/104 Bus Interrupt signal and the CAN-1 SJA1000 CAN controller to the CAN-1 PC/104 Bus Interrupt signal. This mode is set up by removing Jumper J1/J2 Position “S”.

J1/J2 Position “S”	Function
Removed	Dual Interrupt Mode
Installed	Single Interrupt Mode
Table 15

Shared Interrupt Mode

In either the Single or Dual interrupt modes, the PC/104 Bus Interrupt Signal can be shared with a similarly selected interrupt on another PC/104 board (which supports shared interrupts). There are 2 jumpers which control this sharing on J3C Positions #3 and #4.

J3C Position		Function
	Jumper Installed		Jumper Removed
3	CAN-1 Interrupt Shared		CAN-1 Interrupt Not Shared
4	CAN-0 Interrupt Shared		CAN-0 Interrupt Not Shared
Table 16

Shared Interrupt Pull-Down

When shared interrupts are employed, there MUST be one board (among the boards that share the same interrupt) that MUST be setup to activate a Pull-Down resistor on the Interrupt signal. This is accomplished by Jumper J3C Position #5.

J3C Position #5	Function
Removed	Shared Interrupt(s) Pull-Down disabled
Installed	Shared Interrupt(s) Pull-Down enabled
Table 17

Interrupt Selection

In either of the CAN-0 or CAN-1 groups there is 11 possible interrupts that can be selected. The jumpers are numbered by the PC/104 Bus Interrupt number (3, 4, 5, 6, 7, 9, 10, 11, 12, 14 or 15). Only one jumper should be installed in the appropriate group.

CAN Bus Dominant Timeout and Minimum Speed

The CANpro/104 board implements a CAN Bus transceiver which has a “Dominant State timeout feature”. This feature prevents the board from permanently holding the CAN bus in the “Dominant state”. Due to this feature, the minimum CAN Bus data rate supported is 20K bps.

15	www.connecttech.com	CTIM-00043 (0.01) 1/15/2010
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