Memory configuration register (memcr), Memory configuration register (memcr) -27 – Motorola MVME2300 Series User Manual

Page 51

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1-27

1

Memory Configuration Register (MEMCR)

The states of the RD[00:31] DRAM data pins, which have weak internal
pull-ups, are latched by the lower Falcon chip at a rising edge of the power-
up reset and stored in this Memory Configuration register to provide some
information about the system memory. Configuration is accomplished
with external pull-down resistors. This 32-bit read-only register is defined
as follows:

M_SIZE[0:1]

Memory Size. This field is encoded as follows:

M_FREF Block A/B/C/D Fast Refresh. When this bit is set, it

indicates that a DRAM block requires faster refresh rate.
If any of the four blocks requires faster refresh rate then
the ram ref control bit should be set.

REG

Memory Configuration Register - $FEF80404

BIT

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

FIELD

M_

SIZ

E

0

M_

SIZ

E

1

M_

FR
E

F

M_

SP
D

0

M_

SP
D

1

R_
A_
T

Y

P0

R_
A_
T

Y

P1

R_
A_
T

Y

P2

R_
B_
TYP0

R_
B_
TYP1

R_
B_
TYP2

L2
_TYP

E0

L2
_TYP

E1

L2
_T
Y

P

2

L3
_TYP

E3

L2
_P
LL0

L2
_P
LL1

L2
_P
LL2

L2
_P
LL3

FL
SH
P0
_

FL
SH
P1
_

FLS

H

P2
-

OPER

RESET

X

X

1

X

1

1

X

X

1

X

X

X

1

X

X

X

X

X

X

X

X

X

X

X

1

1

X

X

X

1

1

1

M_SIZE[0:1]

Total Memory On Board

0B00

16 Megabytes

0B01

32 Megabytes

0B10

64 Megabytes

0B11

128 Megabytes

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