Model 466-1 Adapter
76 Common Problems And Solutions
For example, for a 128K byte Dual Port RAM mapped to 0x0080 0000 -
0x0081 FFFF in the SBus chassis and to 0x0091 0000 - 0x0092 FFFF in the
VMEbus chassis. The VMEbus processor writes 16-bit values 0x0000,
0x0001, 0x0002, etc., to address locations 910000, 910002, 910004, etc.,
respectively. When the SBus system reads location 800000, it gets 0x8000,
not 0x0000, for data. 0x8000 is the value that was written to 920000 on the
VMEbus. In other words, the lower 64K bytes are swapped with the upper
64K bytes. All 128K bytes can be accessed if the programmer is aware of this
memory swapping.
In this case, the programmer has two options:
Leave it as is, but keep in mind the fact that the upper and lower 64K
bytes are transposed.
Move the Dual Port RAM window so that it begins on an even 64K byte
boundary on each side.
9.4 Bus Error Or Unexpected Status ID (Interrupt Vector)
Returned When Reading IACK Read Register
An interrupt is not asserted for the interrupt level being acknowledged, or
no backplane interrupts are being asserted. Check the
IACK Read Mode
Address
bits in the Remote Status Register accessed by the SBus system,
section 6.2.3.
The IACK daisy chain lost continuity on the VMEbus backplane. Check
the backplane to make sure the IACK daisy chain jumper is installed for
each slot in which no card is installed.
There are contending drivers on the IACK daisy chain. Check the
VMEbus backplane to make sure the IACK daisy chain jumper is removed
from each slot in which a card is installed.
Содержание 466-1
Страница 1: ...Model 466 1 Adapter Hardware Manual Connects a SBus Computer to a VMEbus System...
Страница 2: ...Model 466 1 Adapter ii...
Страница 24: ...Model 466 1 Adapter 14 Adapter Functions...
Страница 52: ...Model 466 1 Adapter 42 VMEbus Adapter Card Configuration...
Страница 70: ...Model 466 1 Adapter 60 CSR Accessed From The SBus...
Страница 88: ...Model 466 1 Adapter 78 Common Problems And Solutions...
Страница 106: ...Model 466 1 Adapter 96 Jumper Configuration Worksheets...
Страница 107: ...Model 466 1 Adapter Jumper Configuration Worksheets 97 D 1 SBus Adapter Card Worksheet J1...
Страница 108: ...Model 466 1 Adapter 98 Jumper Configuration Worksheets...
Страница 110: ...Model 466 1 Adapter 100 Jumper Configuration Worksheets...