•
Socket
Number Bit:
3 2 1
A
0 0 0
B
0 0 1
E
1 0 0
F
1 0 1
•
•
XVME-956 Manual
August 1994
5.7
P R O G R A M M I N G
This section presents reference information to help you understand the XVME-956/101 unit
programming interface. I t also provides information on control register functions and how to read the
registers for power alarm, and battery voltage monitoring. Data is also included on selecting pages
within large memory devices, board number, window address, and Flash
EPROM
programming.
5.8 C O N T R O L REGISTER USAGE
The control registers are I/O mapped, 8-bit registers that enable certain functions and provide
information about others. These functions are discussed in detail in the sections following.
In systems with multiple XVME-956/101 modules, all modules at the same I/O port address receive the
same information in their control registers. However, because Board Number is decoded from the
contents of Control Register 1, only one module per address is selected. A t
power up and CTRL
-
ALT-DEL reset,
the control registers are reset to all zeros by the BIOS.
5.8.1 Control Register 1 Functions
The contents of Control Register 1 selects a particular XVME-956/101 module by board number,
selects a particular socket on that module, and selects "pages" of large devices in that socket.
To select a particular socket, write the lower 3 bits of control register with the desired socket number
(in binary). T h e binary addresses of the sockets are given in Table 5-18.
Table 5-18. Socket Selection
5-19
