Sundance SMT329 - Manual (Page 26)

4.4.2 VME slave interface to the I/O registers
This I/O address space occupies 256 bytes for the basic I/O functions, and a further 768 byte
I/O2 space can be software enabled, to provide VME access to the expanded functions such
as DMA and RSL interfaces.
The I/O space has a base address set by the VME controller in the VME configuration register
“I/O Offset Register”.
This address space is decoded in the VME A32 space, which means that the VME address
modifiers must be set to either of the following:
Hex Code VME
space
Function
0D A32 Extended supervisory data access
09 A32 Extended non privileged data access
The VME address bits are decoded as follows for the basic 256 byte I/O space:
VME
Address
bit Compare to Comment
31-24 1 Must be high
23-8 I/O Base D15-0 16 bit I/O Base programmed by the VME controller
7-1 - Select individual registers in 256 byte space
The VME address bits are decoded as follows for the full 1024 byte I/O space:
VME
Address
bit Compare to Comment
31-24 1 Must be high
23-10 I/O Base D15-2 14 bit I/O Base programmed by the VME controller
9-1 - Select individual registers in 1024 byte space
User Manual SMT329 Page 26 of 52 Last Edited: 09/02/2007 10:58:00