Local Bus To Vmebus Requester Control Register - Motorola MVME162FX Programmer's Reference Manual

Local Bus to VMEbus Requester Control Register

ADR/SIZ
BIT 15
ROBN
NAME
OPER R/W
RESET 0 PS
This register controls the VMEbus request level, the request mode,
and release mode for the local bus to VMEbus interface.
LVREQL
LVRWD
LVFAIR
DWB
$FFF40030 (8 bits [7 used] OF 32)
14 13 12
DHB DWB
R R/W
0 PS 0 PSL
These bits define the VMEbus request level. The
request is only changed when the VMEchip2 is bus
master. The VMEchip2 always requests at the old
level until it becomes bus master and the new level
takes effect. If the VMEchip2 is bus master when the
level is changed, the new level does not take effect
until the bus has been released and re-requested at
the old level. The requester always requests the
VMEbus at level 3 the first time following a
SYSRESET.
0 The request level is 0.
1 The request level is 1.
2 The request level is 2.
3 The request level is 3.
When this bit is high, the requester operates in the
release-when-done mode. When this bit is low, the
requester operates in the release-on-request mode.
When this bit is high, the requester operates in the
fair mode. When this bit is low, the requester does
not operate in the fair mode. In the fair mode, the
requester waits until the request signal line for the
selected level is inactive before requesting the
VMEbus.
When this bit is high, the VMEchip2 requests the
VMEbus and does not release it. When this bit is
low, the VMEchip2 releases the VMEbus according
LCSR Programming Model
11 10 9
LVFAIR LVRWD
R/W R/W
0 PS 0 PS
2
8
LVREQL
R/W
0 PS
2-55