package require Vme
vme create spaceName ?options? baseAddress length
vme delete spaceName
vme list
spaceName get ?sizeoption? offset
spaceName set ?sizeoptions? offset value
The vme create command creates a new command
spaceName that is used to manipulate the contents
of a VME address space starting at baseAddress
and having a size of length bytes. See
OPTIONS below for more information.
vme delete destroys the address space named spaceName. vme list lists the vme space names and their VME base addresses.
Once created an address space is a command with subcommands.
get returns a value from the VME bus
at the byte offset from the base address of the address space
specified by offset, while
set sets a VME location specified by
offset to the value
supplied. The width of the transfer can be controlled. See
OPTIONS for more information.
Two sets of options are important. The vme command options:
The VME addresss selects an addres space along with each address. Potentially the VME address spaces are completely disjoint. Address space values recognized by the -device option are:
All select an address space where only the bottom 16 bits are decoded. Note that often peripherals live in this space and may only have 16 bit transfer paths.
All select an address space where only the bottom 24 bits are decoded.
Select an address spacewhere all 32 bits of address are decoded.
Selects the address space normally used for goegrphical addressing.
Provids the VME crate number. The crate numer is 0 if not supplied.
The options for get/set on an address space command are:
Transfer 32 bits (a longword).
Transfer 16 bits (a word).
Transfer 8 bits (a byte).