Programming Model

Revision ID/ General Control Register

Address

 

 

 

 

 

 

 

 

 

 

 

 

 

 

$FEF80008

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bit

0

1

2

3

4

5

6

7

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10

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14

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20

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31

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Name

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

0

0

0

0

0

aonlyen

 

isahole

0

0

0

 

adis

 

ramfref

 

ramspd0

 

ramspd1

chipu

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

REVID

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Operation

 

READ ZERO

 

 

READ ONLY

 

R

R

R

R

R

R

R

R/W

R

R

R

R/W

R/W

R/W

R/W

R

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset

 

 

 

X

 

 

 

 

X

 

 

 

X

X

X

X

X

X

V

0

X

X

X

0

1

0

0

V

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

P

PL

 

 

 

P

P

P

P

P

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

REVID The REVID bits are hard-wired to indicate the revision level of the Falcon. The values are $01 for the first revision, $02 for the second.

aonly_en Normally, the Falcon pair responds to address-only cycles only if they fall within the address range of one of its enabled map decoders. When the aonly_en bit is set, the Falcon pair also responds to address-only cycles that fall outside of the range of its enabled map decoders provided they are not acknowledged by some other slave within 8 clock periods. aonly_en is read-only and reflects the level that was on the CKD4 pin at power-up reset.

isa_hole When it is set, isa_hole disables any of the DRAM or ROM/Flash blocks from responding to PowerPC accesses in the range from $000A0000 to $000BFFFF. This has the effect of creating a hole in the DRAM memory map for accesses to ISA. When isa_hole is cleared, there is no hole created in the memory map.

adis When adis is clear, fast page mode operation is used for back-to-back pipelined accesses to the same page within DRAM. When it is set, RAS is cycled between accesses. This bit should normally be cleared unless the Falcon has a problem operating that way.

3

http://www.motorola.com/computer/literature

3-31

Page 193
Image 193
Motorola MVME2300 Series manual Revision ID/ General Control Register, Read Zero Read only