Register Descriptions
Chapter 4
VXI-MXI User Manual
4-4
© National Instruments Corporation
VXIbus Configuration Registers
These registers are defined by the VXIbus specification for all VXIbus devices.
VXIbus ID Register
VXIbus Address:
Base A 0 (hex)
Attributes:
Read Only
R
15
14
13
12
11
10
9
0
1
1
1
1
1
1
1
8
DEVCLASS
ADDR
MANID
7
6
5
4
3
2
1
0
0
1
1
1
1
1
1
0
This register provides information about this device and its configuration. The bits in this
register are configured in hardware as shown above. Hard and soft resets have no effect on this
register.
Bit
Mnemonic
Description
15-14r
DEVCLASS
Device Class Bits
These bits indicate the device class of the VXIbus device as
follows:
00 = Memory
01 = Extended
10 = Message-Based
11 = Register-Based
The VXI-MXI is an extended device defined by National
Instruments; therefore, these bits are configured in hardware as
binary 01.
13-12r
ADDR
Address Space Bits
These bits indicate the address spaces in which the VXIbus device
has operational registers as follows:
00 = A16/A24
01 = A16/A32
10 = Reserved
11 = A16 Only
The VXI-MXI has operational registers in A16 only; therefore,
these bits are configured in hardware as binary 11.