LCSR Programming Model

 

 

DLOB

When this bit is set, the DMAC received a TEA and the

 

status indicated off-board. This bit is cleared when the

 

DMAC is enabled.

DLPE

When this bit is set, the DMAC received a TEA and the

 

status indicated a parity error during a DRAM data

 

transfer. This bit is cleared when the DMAC is enabled.

 

This bit is not defined for MVME172 implementation.

DLBE

When this bit is set, the DMAC received a TEA and

 

additional status was not provided. This bit is cleared

 

when the DMAC is enabled.

MLTO

When this bit is set, the MPU received a TEA and the

 

status indicated a local bus time-out. This bit is cleared by

 

a writing a one to the MCLR bit in this register.

2

Programming the Tick and Watchdog Timers

The VMEchip2 has two 32-bit tick timers and one watchdog timer. This section provides addresses and bit level descriptions of the prescaler, tick timer, watchdog timer registers and various other timer registers.

VMEbus Arbiter Time-out Control Register

ADR/SIZ

 

 

$FFF4004C (8 bits [1 used] of 32)

 

 

BIT

31

30

29

28

27

26

25

24

 

 

 

 

 

 

 

 

 

NAME

 

 

 

 

 

 

 

ARBTO

 

 

 

 

 

 

 

 

 

OPER

 

 

 

 

 

 

 

R/W

 

 

 

 

 

 

 

 

 

RESET

 

 

 

 

 

 

 

0 PS

 

 

 

 

 

 

 

 

 

This register controls the VMEbus arbiter time-out timer.

ARBTO

When this bit is high, the VMEbus grant time-out timer is

 

enabled. When this bit is low, the VMEbus grant timer is

 

disabled. When the timer is enabled and the arbiter does

 

not receive a BBSY signal within 256 μs after a grant is

 

issued, the arbiter asserts BBSY and removes the grant.

 

The arbiter then rearbitrates any pending requests.

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Image 143
Motorola MVME172 manual Programming the Tick and Watchdog Timers, VMEbus Arbiter Time-out Control Register