User guide

Table 10–14 Local Bus A1,0 and SIZ1,0 to PCI BE# Translation
Local Bus
A1,0 SIZ1,0 Data
Mode 0
BE#
Mode 1
BE#
Mode 2
BE#
Mode 3
BE#
00 00 D[31:0] 0000 0000 0000 0000
00 11 D[31:8] 1000 0100 0010 0001
01 11 D[23:0] 0001 0010 0100 1000
00 10 D[15:0] L 1100 1100 0011 0011
01 10 D[23:8] 1001 0110 0110 1001
10 10 D[15:0] 0011 0011 1100 1100
00 01 D[15:8] L 1110 1101 1011 0111
01 01 D[7:0] L 1101 1110 0111 1011
10 01 D[15:8] 1011 0111 1110 1101
11 01 D[7:0] 0111 1011 1101 1110
10.5 Initializing the VME Interface
The Digital Alpha VME 4 firmware must set up some registers in the VME
interface as fixed configuration values. This section describes these registers and
other VME interface initialization.
The firmware uses the following procedure to set up the VME interface for use
with the default values for the DC7407 registers:
1. Set up the three PCI base registers in the VME interface.
2. Program scatter-gather RAM as needed.
3. Configure the VIC64 for initialization. Some timing control register values
are defined.
4. Operate the VME interface.
10.5.1 VME PCI Configuration Registers
CPU Address: 0x1E0000000 - 0x1E0001FE0
PCI Configuration: 0x00000800 - 0x000008FF
The PCI bus interface to VMEbus must be configured at startup by writing three
base address registers within the DC7407. A fourth register can be used to read
the hardware setting for the second VME window if required. These registers are
accessible only through PCI configuration address space. Once these registers are
initialized, PCI memory space can be used to set up the remainder of the VME
subsystem for access to VME devices.
10–30 VME Interface