OFFSET Ox00
I
D
Reg.
bit #
15-14
13-12
11-0
use of field
device class
addressing modes
manufacturer's ID
TFP meaning
Register Based
A16 only
OxEF4
RESET VALUE OxFEF4
This register was implemented to satisfy the VXlbus Specification. B i t assignments are as follows.
OFFSET 0x02 D E V I C E
RESET VALUE OxF350
This register simply contains (in the case of an A16 only device) a manufacturer's card ID.
OFFSET 0x04 S T A T U S
R
E
S
E
T
VALUE OxFFFF
The TFP does not support VXIbus initialization and diagnostic features. The reset value is always
returned.
OFFSET 0x04 C O N T R O L
Writing to this register with bit 0 set will deassert any pending interrupts and will clear all used bits
in offsets 0x20 through Ox2E (except FIFO at offset 0x28). Writing to this register with bit 0 cleared
has no effect. A l l other bits are ignored during a write.
RESET VALUE OxFFFE
OFFSET OxOA T I M E R E Q
R
E
S
E
T
VALUE NA
Reading this register latches the current time and status into offsets OxOC through Ox14. The value
read is indeterminant.
*** WARNING ***
Many compilers will optimize out of existence an assignment made to a local variable i f that
variable is not used. For example, the following code snippet may not read offset OxOA.
timeptr = (short *)(BASE + OxOA) ;
local dummy = *+ ;
read time(timeptr) ;
I*
initialize pointer */
/* latch the time ?? */
/* read the time */
The following form is recommended. Use of the global prevents optimizing out.
timeptr = (short *) (BASE + OxOA) ;
global dummy = *+ ;
read time(timeptr) ;
I*
initialize pointer */
/* latch the time */
/* read the time */
Datum Inc., Bancomm Div.
bc635VME/bc350VXI Manual
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