Dmac Ton/Toff Timers And Vmebus Global Time-Out Control Register - Motorola MVME1X7P Programmer's Reference Manual

DMAC Ton/Toff Timers and VMEbus Global Time-out Control Register

ADR/SIZ
BIT
23
NAME
OPER
RESET
This register controls the DMAC time off timer, the DMAC time on timer,
and the VMEbus global time-out timer.
VGTO
TIME ON
TIME OFF
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$FFF4004C (8 bits of 32)
22 21
TIME OFF
R/W
0 PS
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 s
1 64 s
2 256 s
3 The timer is disabled
These bits define the maximum time the DMAC spends
on the VMEbus:
0 16 s
1 32 s
2 64 s
3 128 s
These bits define the minimum time the DMAC spends
off the VMEbus:
0 0 s
1 16 s
2 32 s
3 64 s
LCSR Programming Model
20 19 18
TIME ON
R/W
0 PS
4 256 s
5 512 s
6 1024 s
7 When done (or no data)
4 128 s
5 256 s
6 512 s
7 1024 s
17 16
VGTO
R/W
0 PS
2-65
2