User's Manual

PMAC VME Hardware Reference Manual

PMAC VME Connector Pinouts 21

J3 JTHW Connector (26-Pin Connector)

Front View

Pin # Symbol Function Description Notes

1 GND Common PMAC Common

2 GND Common PMAC Common

3 DAT0 Input Data-0 Input Data input from thumbwheel switches

4 SEL0 Output Select-0 Output Scanner output for reading TW switches

5 DAT1 Input Data-1 Input Data input from thumbwheel switches

6 SEL1 Output Select-1 Input Scanner output for reading TW switches

7 DAT2 Input Data-2 Input Data input from thumbwheel switches

8 SEL2 Output Select-2 Output Scanner output for reading TW switches

9 DAT3 Input Data-3 Input Data input from thumbwheel switches

10 SEL3 Output Select-3 Output Scanner output for reading TW switches

11 DAT4 Input Data-4 Input Data input from thumbwheel switches

12 SEL4 Output Select-4 Output Scanner output for reading TW switches

13 DAT5 Input Data-5 Input Data input from thumbwheel switches

14 SEL5 Output Select-5 Output Scanner output for reading TW switches

15 DAT6 Input Data-6 Input Data input from thumbwheel switches

16 SEL6 Output Select-6 Output Scanner output for reading TW switches

17 DAT7 Input Data-7 Input Data input from thumbwheel switches

18 SEL7 Output Select-7 Output Scanner output for reading TW switches

19 N.C. N.C. No Connection

20 GND Common PMAC Common

21 BRLD/ Output Buffer Request Low is "Buffer Request

22 GND Common PMAC Common

23 IPLD/ Output In Position Low is In Position

24 GND Common PMAC Common

25 +5V Output +5VDC Supply Power supply out

26 INIT/ Input PMAC Reset Low is Reset

The JTHW multiplexer port provides eight inputs and eight outputs at TTL levels. While these I/O can be used in

un-multiplexed form for 16 discrete I/O points, most users will utilize PMAC software and accessories to use this

port in multiplexed form to greatly multiply the number of I/O that can be accessed on this port. In multiplexed

form, some of the SELn outputs are used to select which of the multiplexed I/O are to be accessed.