Local Bus To Vmebus I/O Control Register - Motorola MVME172 Programmer's Reference Manual

VMEchip2

Local Bus to VMEbus I/O Control Register

2
ADR/SIZ
BIT
NAME
OPER
RESET
2-50
15 14 13
I2EN I2WP I2SU
R/W R/W R/W
0 PSL 0 PS O PS
This register controls the VMEbus short I/O map and the F page
($F0000000 through $FF7FFFFF) I/O map.
I1SU When this bit is high, the VMEchip2 drives a supervisor
address modifier code when the short I/O space is
accessed. When this bit is low, the VMEchip2 drives a
user address modifier code when the short I/O space is
accessed.
I1WP When this bit is high, write posting is enabled to the
VMEbus short I/O segment. When this bit is low, write
posting is disabled to the VMEbus short I/O segment.
I1D16 When this bit is high, D16 data transfers are performed to
the VMEbus short I/O segment. When this bit is low, D32
data transfers are performed to the VMEbus short I/O
segment.
I1EN When this bit is high, the VMEbus short I/O map decoder
is enabled. When this bit is low, the VMEbus short I/O
map decoder is disabled.
I2PD When this bit is high, the VMEchip2 drives a program
address modifier code when the F page is accessed. When
this bit is low, the VMEchip2 drives a data address
modifier code when the F page is accessed.
I2SU When this bit is high, the VMEchip2 drives a supervisor
address modifier code when the F page is accessed. When
this bit is low, the VMEchip2 drives a user address
modifier code when the F page is accessed.
$FFF4002C (8 bits of 32)
12 11
I2PD I1EN
R/W R/W
0 PS 0 PS
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10 9 8
I1D16 I1WP I1SU
R/W R/W R/W
O PS 0 PS O PS