User manual

Chapter 5 Register Descriptions

VXIbus Device Type Register (VDTR)

VXIbus Configuration Offset: 2 (hex)

Attributes: Read Only 16, 8-bit accessible

15 14 13 12 11 10 9 8

REQMEM[3] REQMEM[2] REQMEM[1] REQMEM[0] MODEL[11] MODEL[10] MODEL[9] MODEL[8]

76 54 321 0

MODEL[7] MODEL[6] MODEL[5] MODEL[4] MODEL[3] MODEL[2] MODEL[1] MODEL[0]

This register contains information about the VXI-MXI-2 that indicates the amount of

required address space and identifies the model code of the VXI-MXI-2. This register

conforms to the VXIbus specification. Hard and soft resets have no effect on this register.

Bit Mnemonic Description

15-12 REQMEM[3:0] Required Memory

These bits determine the amount of memory

space that will be requested by the VXI-MXI-2

in either A24 or A32 address space as

determined by the Address Space bits

(ADSPC[1:0]) in the VXIbus ID Register

(VIDR). The amount of space requested will be

256

ADSPC[1:0]

* 2

(23 - REQMEM[3:0])

bytes. Refer

to Chapter 7, VXIplug&play for the VXI-MXI-2,

or Appendix B, Programmable Configurations,

for information on configuring the required

memory of the VXI-MXI-2.

11-0 MODEL[11:0] Model Code

These bits return a unique code assigned to the

VXI-MXI-2 by National Instruments. To meet

the VXIbus specification requirement that a Slot

0 device’s model code be in the range 0 to FF

(hex), these bits return 0EA (hex)—or 0E8 (hex)

for the VXI-MXI-2/B—when in slot 0, and FEA

(hex)—or FE8 (hex) for the VXI-MXI-2/B—

when not in slot 0.