2

VMEchip2

 

 

SNP

 

 

 

These bits control the snoop signal lines on the local bus

 

 

 

 

 

 

when the DMAC is local bus master and it is not accessing

 

 

 

 

 

 

the command table. The snooping functions differ

 

 

 

 

 

 

 

 

according to processor type, as shown:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SNP

 

 

 

Requested Snoop Operation

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

14

 

13

 

 

 

MC68040

 

 

 

 

MC68060

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

 

0

Snoop disabled

 

 

 

Snoop enabled

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

 

1

Source dirty, sink byte/word/longword

Snoop disabled

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

0

Source dirty, invalidate line

 

 

 

Snoop enabled

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

1

Snoop disabled (Reserved)

 

 

 

Snoop disabled

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

INTE

This bit is used only in command chaining mode. It is only

 

 

 

 

 

 

modified when the DMAC loads the control register from

 

 

 

 

 

 

the control word in the command packet. When this bit in

 

 

 

 

 

 

the command packet is set, an interrupt is sent to the local

 

 

 

 

 

 

bus interrupter when the command in the packet has been

 

 

 

 

 

 

executed. The local bus is interrupted if the DMAC

 

 

 

 

 

 

 

 

interrupt is enabled.

 

 

 

 

 

 

 

 

DMAC Control Register 2 (bits 0-7)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ADR/SIZ

 

 

 

 

 

 

$FFF40034 (8 bits of 32)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BIT

7

 

 

6

 

5

 

4

 

3

 

2

 

1

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NAME

 

BLK

 

 

 

 

 

VME AM

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OPER

 

R/W

 

 

 

 

 

R/W

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RESET

 

0 PS

 

 

 

 

 

0 PS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This portion of the control register is loaded by the processor or the DMAC when it loads the command word from the command packet. Because this byte is loaded from the command packet in command chaining mode, the descriptions here also apply to the control word in the command packet.

VME AM These bits define the address modifier codes the DMAC drives on the VMEbus when it is bus master. During non-block transfer cycles, bits 0-5 define the VMEbus address modifiers. During block transfers, bits 2-5 define

2-58

Computer Group Literature Center Web Site

Page 148
Image 148
Motorola MVME1X7P manual Snp, Inte, This bit is used only in command chaining mode. It is only