User manual

Chapter 6 System Configuration

devices. VXIbus Mainframe #3 needs 4 KB of A16, in addition to

the amount of A16 required by MXIbus link #3 connected to it on

Level 2.

4. Figure 6-23 is the worksheet for MXIbus #3, which includes

VXIbus Mainframes #4 and #5. Mainframe #4 needs 2 KB and

Mainframe #5 needs 1 KB of A16 space. We fill in the appropriate

spaces on the worksheet.

5. Now we return to Figure 6-22 and fill in the MXIbus #3

information in the space for a second-level MXIbus link connected

to VXIbus Mainframe #3. MXIbus #3 needs 2 KB for Mainframe

#4 and 1 KB for Mainframe #5. The sum is 3 KB, which rounds up

to the next address break of 4 KB. The amount of A16 space

required for the window into VXIbus Mainframe #3 is 4 KB plus

the 3 KB required by MXIbus #3, which rounds up to the next

address break of 8 KB. We enter all of these numbers into the

worksheet.

6. We now fill in Figure 6-21 for MXIbus #1. MXIbus #1 requires

512 bytes for MXIbus Device A and 8 KB for VXIbus

Mainframe #3. The sum of these values rounds up to the nearest

address break of 16 KB. We record this information on the

worksheet.

7. Figure 6-21 is now completed for MXIbus #2. The only device on

MXIbus #2 is VXIbus Mainframe #6, which needs 2 KB of A16

space. We enter this value into the worksheet.

8. The total amount of A16 space required by the system is now

computed and found to be 34 KB, which rounds up to the next

address break of 48 KB. This number does not exceed the

maximum of 48 KB, so this configuration of A16 space is

acceptable.

9. The next step is to determine the range of addresses, or base

address, size, and direction of the A16 window for each

VXI-MXI-2 in the system. We first assign A16 space to the

VXIbus RM Mainframe. From Figure 6-21, we see it needs

16 KB of A16 space, so we assign it the bottom 16 KB of A16

space, addresses 0 through 3FFF hex. See Figure 6-20 for a

pictorial representation of this assignment.