Motorola MVME172 manual DMA Status Register, Ipto

Models: MVME172

1 354
Download 354 pages 60.32 Kb
Page 270
Image 270

4

IP2 Chip

DMA Status Register

ADR/SIZ

 

$FFFBC020, $38, $50, $68 (8 bits each)

 

 

 

 

 

 

 

 

 

 

BIT

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

 

NAME

0

DLBE

0

IPEND

CHANI

TBL

IPTO

DONE

 

 

 

 

 

 

 

 

 

OPER

R

R

R

R

R

R

R

R

 

 

 

 

 

 

 

 

 

RESET

0 R

0 R

0 R

0 R

0 R

0 R

0 R

1 R

 

 

 

 

 

 

 

 

 

 

DONE

This bit is set when DMAC has finished executing

 

 

commands and there were no errors, or DMAC has

 

 

finished executing commands because the DHALT bit

 

 

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

 

 

DMAC interrupt will be generated if interrupts are

 

 

enabled.

 

 

 

 

 

 

IPTO

When this bit is set, a DMAC access to an IndustryPack

 

 

timed out. This bit is cleared when DMA is enabled. A

 

 

DMAC interrupt will be generated if interrupts are

 

 

enabled.

 

 

 

 

 

 

TBL

When this bit is set, DMAC received an error on the local

 

 

bus while it was reading commands from the command

 

 

packet. Additional information is provided in bit 6

 

 

(DLBE). This bit is cleared when DMAC is enabled.

 

DLBE

When this bit is set, DMAC received a TEA. (TEA is

 

 

transfer error acknowledge signal on the MC68060 local

 

 

bus. It indicates that a time-out occurred.) This bit is

 

 

cleared when DMAC is enabled. A DMAC interrupt will

 

 

be generated if interrupts are enabled.

 

 

CHANI When this bit is set, the INTE bit in the DMA Control Register 2 was detected. This bit is cleared when DMA is enabled or the interrupt status bit is cleared in the DMA interrupt control register or the DHALT bit was detected in the DMA Control Register 1. A DMAC interrupt will be generated if interrupts are enabled.

4-34

Computer Group Literature Center Web Site

Page 270
Image 270
Motorola MVME172 manual DMA Status Register, Ipto