Motorola MVME1X7P manual Lvrwd, Lvfair, Dwb, Dhb, Robn

Models: MVME1X7P

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LCSR Programming Model

0 The request level is 0.

1 The request level is 1.

2 The request level is 2.

3 The request level is 3.

 

 

LVRWD

 

When this bit is high, the requester operates in

 

 

 

 

 

 

release-when-done mode. When this bit is low, the

 

 

 

 

 

 

requester operates in release-on-request mode.

 

 

 

LVFAIR

 

When this bit is high, the requester operates in fair mode.

 

 

 

 

 

When this bit is low, the requester does not operate in fair

 

 

 

 

 

mode. In fair mode, the requester waits until the request

 

 

 

 

 

signal line for the selected level is inactive before

 

 

 

 

 

 

requesting the VMEbus.

 

 

 

 

 

 

 

 

DWB

 

When this bit is high, the VMEchip2 requests the

 

 

 

 

 

 

VMEbus and does not release it. When this bit is low, the

 

 

 

 

 

VMEchip2 releases the VMEbus according to the release

 

 

 

 

 

mode programmed in the LVRWD bit. When the

 

 

 

 

 

 

VMEbus has been acquired, the DHB bit is set.

 

 

 

DHB

 

When this bit is high, the VMEbus has been acquired in

 

 

 

 

 

response to the DWB bit being set. When the DWB bit is

 

 

 

 

 

cleared, this bit is cleared.

 

 

 

 

 

ROBN

 

When this bit is high, the VMEbus arbiter operates in

 

 

 

 

 

round-robin mode. When this bit is low, the arbiter

 

 

 

 

 

 

operates in priority mode.

 

 

 

DMAC Control Register 1 (bits 0-7)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ADR/SIZ

 

 

 

 

$FFF40030 (8 bits of 32)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BIT

7

 

6

 

5

4

 

3

 

2

1

 

0

 

NAME

DHALT

 

DEN

 

DTBL

DFAIR

 

 

DRELM

DREQL

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OPER

S

 

S

 

R/W

R/W

 

 

R/W

R/W

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RESET

0 PS

 

0 PS

 

0 PS

0 PS

 

 

0 PS

0 PS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This control register is loaded by the processor; it is not modified when the DMAC loads new values from the command packet.

DREQL These bits define the VMEbus request level for the DMAC requester. The request level can only change while the VMEchip2 is bus master. The VMEchip2

2

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Page 145
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Motorola MVME1X7P manual Lvrwd, Lvfair, Dwb, Dhb, Robn