Revision id/ general control register, Revision id/ general control register -31, Universe register map -9 – Motorola MVME2300 Series User Manual

Page 193

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Programming Model

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3-31

3

Revision ID/ General Control Register

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.

Address

$FEF80008

Bit

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

Name

REVID

0

0

0

0

0

0

ao
nl

y_
en

isa
_

h

o

le

0

0

0

ad
is

ram

fre

f

ra

m

s

pd0

ra

m

s

pd1

ch
ip

u

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 P

0 PL

X

X

X

0 P

1 P

0 P

0 P

V P

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