User guide

Table 10–13 PCI BE# to Local A1,0 and SIZ1,0 Translation for Various Swap
Modes
PCI
BE#
<3:0>
Mode 0
No Swap
A1,0
SIZ1,0
Mode 1
Byte Swap
A1,0 SIZ1,0
Mode 2
Word Swap
A1,0 SIZ1,0
Mode 3
Longword
Swap
A1,0 SIZ1,0
1111 No cycle No cycle No cycle No cycle
1110 00 01 L 01 01 L 10 01 11 01
1101 01 01 L 00 01 L 11 01 10 01
1011 10 01 11 01 00 01 L 01 01 L
0111 11 01 10 01 01 01 L 00 01 L
1100 00 10 L 00 10 L 10 10 10 10
1001 01 10 Noncontig Noncontig 01 10
0011 10 10 10 10 00 10 L 00 10 L
1000 00 11 Noncontig Noncontig 01 11
0001 01 11 Noncontig Noncontig 00 11
0000 00 00 00 00 00 00 00 00
0101 Noncontig Noncontig Noncontig Noncontig
1010 Noncontig Noncontig Noncontig Noncontig
0110 Noncontig 01 10 01 10 Noncontig
0010 Noncontig 01 11 00 11 Noncontig
0100 Noncontig 00 11 01 11 Noncontig
As a VMEbus slave or during DMA-driven block mode transfers, the VIC64
drives the local bus address lines and the DC7407 generates the byte-enable
combinations to drive onto the PCI bus. In some cases, the translations may
result in noncontiguous byte-enable arrangements on the PCI bus. These are
passed to the PCI bus with the corresponding byte enables asserted. As shown in
Table 10–14, the data for byte and aligned words is always received on the data
lines D[15:0].
VME Interface 10–29