Operating In Register-Based Mode - Racal Instruments 1260-X121 User Manual

1260-X121 User Manual
Operating in
Register-Based
Mode
Racal Instruments © 2005
The 1260-X121 offers register-based mode when installed in VXI
platforms that support it. In register-based mode, the 1260-X121 is
operated by directly writing and reading to/from ports controlling up
to eight relays each. To access the registers the following details
must be assembled to generate an absolute address that can be
wrote or read from:
The port and control registers are located in the VXIbus A24
Address Space. The A24 address for a port or control register
depends on:
1. The A24 Address Offset assigned to the 1260-01T module by
the Resource Manager program. The Resource Manager
program is provided by the VXIbus slot-0 controller vendor.
The A24 Address Offset is placed into the "Offset Register" of
the 1260-01T by the Resource Manager.
2. The <module address> of the 1260-X121 module. This is a
value in the range from 1 and 12 inclusive.
3. The 1260-X121 control register to be written to or read from.
Each register on the 1260-X121 has a unique offset from the
base address.
The base A24 address for the 1260-X121 module may be
calculated by:
(A24 Offset of the 1260-01T) + (1024 x Module Address of
1260-121).
The A24 address offset is usually expressed in hexadecimal. A
typical value of 204000
A 1260-X121 with a module address of 7 would have the base A24
address computed as follows:
Base A24 Address of 1260-X121 = 204000
= 205C00
16
The port and control registers for Adapt-a-Switch plug-ins and
conventional 1260-Series modules are always on odd-numbered
A24 addresses. For port registers, the 1260-X121 reads and
writes to the same location. For control registers, the 1260-X121
writes to one location, but reads back from another. Table 3-1 and
3-5 provides offsets relative to the base address of the module for
all port and control registers of the 1260-121.
absolute address where data is to be written or read from, the base
address is added to the offset:
(Base A24 1260-X121 Address) + offset = absolute
is used in the examples that follow.
16
+ (400 x 7
16 16 10
To obtain the
Module Operation 3-3
)