A32 Window Map Register - National Instruments VXI-MXI User Manual

Register Descriptions

A32 Window Map Register

VXIbus Address:
Attributes:
This register defines the range of addresses in A32 space that are mapped into and out of the
VXI-MXI through the MXIbus. These bits are cleared on a hard reset.
The CMODE bit in the MXIbus Control Register selects the format of this register. If the
CMODE bit is 0 (default), a Base/Size window comparison is used to determine the range of
addresses in the window. If the CMODE bit is set, an upper and lower bound is used to
determine the range of addresses in the window.
The A32 Window Map Register has the following format when the CMODE bit is cleared:
15 14
0 A32EN
A32EN
0
6
7
A32BASE7 A32BASE6 A32BASE5 A32BASE4 A32BASE3 A32BASE2 A32BASE1 A32BASE0
Bit Mnemonic
15r/w 0
14r/w A32EN
13r/w A32DIR
VXI-MXI User Manual
Base Address + 10 (hex)
Read/Write
13 12
A32DIR 1
A32DIR 0
5 4
Description
Reserved Bit
This bit is reserved and reads back as zero. Write a zero when
writing to these bits.
A32 Window Enable Bit
When this bit is set, the A32 mapping window is enabled. When
this bit is cleared, the A32 mapping window is disabled.
A32 Window Direction Bit
When this bit is set, the A32 window applies to MXIbus cycles that
are mapped into VXIbus cycles (inward cycles). When this bit is
cleared, the A32 window applies to VXIbus cycles that are mapped
out into MXIbus cycles (outward cycles). The complement of the
defined range is mapped in the opposite direction.
11 10
1 A32SIZE2
0 A32SIZE2
3 2
4-22 © National Instruments Corporation
Chapter 4
9 8
R
A32SIZE1 A32SIZE0
A32SIZE1 A32SIZE0
W
1 0
R/W