2-66
Computer Group Literature Center Web Site
VMEchip2
2
DMAC Ton/Toff Timers and VMEbus Global Time-out Control Register
This register controls the DMAC time off timer, the DMAC time on timer,
and the VMEbus global time-out timer.
VGTO
These bits define the VMEbus global time-out value.
When DS0 or DS1 is asserted on the VMEbus, the timer
begins timing. If the timer times out before the data
strobes are removed, a BERR signal is sent to the
VMEbus. The global time-out timer is disabled when the
VMEchip2 is not system controller.
0
8
µ
s
1
64
µ
s
2
256
µ
s
3
The timer is disabled
TIME ON
These bits define the maximum time the DMAC spends
on the VMEbus:
0
16
µ
s
4
256
µ
s
1
32
µ
s
5
512
µ
s
2
64
µ
s
6
1024
µ
s
3
128
µ
s
7
When done (or no data)
TIME OFF
These bits define the minimum time the DMAC spends
off the VMEbus:
0
0
µ
s
4
128
µ
s
1
16
µ
s
5
256
µ
s
2
32
µ
s
6
512
µ
s
3
64
µ
s
7
1024
µ
s
ADR/SIZ
$FFF4004C (8 bits of 32)
BIT
23
22
21
20
19
18
17
16
NAME
TIME OFF
TIME ON
VGTO
OPER
R/W
R/W
R/W
RESET
0 PS
0 PS
0 PS
Содержание MVME172
Страница 1: ...MVME172 VME Embedded Controller Programmer s Reference Guide VME172A PG2 Edition of February 1999 ...
Страница 6: ...Place holder ...
Страница 18: ...xviii ...
Страница 78: ...1 60 Computer Group Literature Center Web Site Board Description and Memory Maps 1 ...
Страница 332: ...5 42 Computer Group Literature Center Web Site MCECC 5 ...
Страница 336: ...A 4 Related Documentation A ...
Страница 340: ...VMEchip2 Tick Timer 1 Periodic Interrupt Example B 4 Computer Group Literature Center Web Site B ...
Страница 352: ...Index IN 12 Computer Group Literature Center Web Site I N D E X ...
Страница 354: ......