LCSR Programming Model

DMAIC The DMAC interrupt counter is incremented when an interrupt is sent to the local bus interrupter. The value in this counter indicates the number of commands processed when the DMAC is operated in command chaining mode. If the interrupt count exceeds 15, the counter rolls over. This counter operates regardless of whether the DMAC interrupts are enabled. This counter is cleared when the DMAC is enabled.

DMAC Status Register

ADR/SIZ

 

 

$FFF40048 (8 bits of 32)

 

 

BIT

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

 

NAME

MLTO

DLBE

DLPE

DLOB

DLTO

TBL

VME

DONE

 

 

 

 

 

 

 

 

 

OPER

R

R

R

R

R

R

R

R

 

 

 

 

 

 

 

 

 

RESET

0 PS

0 PS

0 PS

0 PS

0 PS

0 PS

0 PS

0 PS

 

 

 

 

 

 

 

 

 

 

This is the DMAC status register.

 

 

 

 

 

DONE

This bit is set when the DMAC has finished executing

 

 

commands, either without errors or because the halt bit

 

 

was set. This bit is cleared when the DMAC is enabled.

 

VME

If this bit is set, the DMAC has received a VMEbus BERR

 

 

during a data transfer. This bit is cleared when the DMAC

 

 

is enabled.

 

 

 

 

 

 

TBL

If this bit is set, the DMAC has received an error on the

 

 

local bus while it was reading commands from the

 

 

command packet. Additional information is provided in

 

 

bits 3 - 6 (DLTO, DLOB, DLPE, and DLBE). This bit is

 

 

cleared when the DMAC is enabled.

 

 

 

DLTO

If this bit is set, the DMAC has received a TEA and the

 

 

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

 

 

when the DMAC is enabled.

 

 

 

 

DLOB

If this bit is set, the DMAC has received a TEA and the

 

 

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

 

 

DMAC is enabled.

 

 

 

 

2

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Motorola MVME1X7P manual Dmac Status Register