Motorola MVME172 - Manual (Page 128)

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VMEchip2
2
Local Bus to VMEbus I/O Control Register
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.
ADR/SIZ $FFF4002C (8 bits of 32)
BIT 15 14 13 12 11 10 9 8
NAME I2EN I2WP I2SU I2PD I1EN I1D16 I1WP I1SU
OPER R/W R/W R/W R/W R/W R/W R/W R/W
RESET 0 PSL 0 PS O PS 0 PS 0 PS O PS 0 PS O PS