Xycom XVME-240, Manual

Page: 33 / 73

XVME-240 Manual
October, 1984
Bit 2: Read Only This bit acts as a flag to show if there are any
interrupts pending on the DIO. A logic "1" indicates
that at least one interrupt is pending.
A logic " 0 "
indicates that there are no pending interrupts. This bit
is valid even when interrupts are disabled.
Bit 1, Bit 0: Read/Write These bits control the red LED and green LED. The red
and green LEDs provide a visual indication of module
status.
-
A logic "0" turns on the red LED (bit DO).
- A logic "1" turns on the green LED (bit D1).
The LEDs will work with user-provided diagnostic soft-
ware to indicate module operational status in the
following manner:
Status Bits
1 0
0 0
0 1
1 0
LEDs
Green Red SYSFAIL*
OFF ON O N
O F F O F F O F F
ON ON O N
O N O F F O F F
Status
Module failed, or not yet
tested
Inactive module
Module undergoing test
Module passed test
NOTE
The DIO is a non-intelligent module so all diagnos-
tics and configuration checking must be performed
by the system host.
3.3.3 Module I/O Ports Base A 88H to 8FH)
The 64 I/O channels used by the DIO module are divided into 8 bidirectional ports with
8 channels to a port. These I/O ports are numbered 0 thru 7. Figure 3-1 shows that
the module I/O ports are addressed consecutively within the module I/O Interface
Block from 88H to 8FH. Table 3-1 lists the I/O Interface Block addresses assigned to
each bidirectional port.
Table 3-l. Module I/O Port Addresses
Module I/O Port.
.
0
1
2
3
4
5
6
7
I/O Interface Block Address
88H
89H
8AH
8BH
8CH
8DH
8EH
8FH
Any I/O port can be accessed by adding the module base address to the particular I/O
Interface Block offset for that port. For
example, I/O port 3 is located at address 8BH
3-6