National Instruments SCXI-1121 - Manual (Page 88)

Chapter 4 Register Descriptions
SCXI-1121 User Manual 4-6 www.natinst.com
Slot-Select Register
The Slot-Select Register contains 16 bits that determine which module in which chassis will
be enabled for communication when the SLOT0SEL* line is set to one. An SCXI-1000
chassis will select the appropriate module in its chassis, regardless of the chassis number
written. The Slot-Select Register will shift in the data present on the MOSI line, bit 16 first,
when SLOT0SEL* is cleared to zero.
Type: Write-only
Word Size: 16-bit
Bit Map:
Bit Name Description
15-9 X Don’t care bits.
8-4 CHS<4..0> Chassis Bit 4 through 0—These bits determine which
chassis is selected. On the SCXI-1000 chassis, these bits
are don’t cares.
3-0 SL<3..0> Slot Bit 3 through 0—These bits determine which slot in
the selected chassis is selected.
15 14 13 12 11 10 9 8
X X X X X X X CHS4
7 6 5 4 3 2 1 0
CHS3 CHS2 CHS1 CHS0 SL3 SL2 SL1 SL0