Programming Model

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:

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 SIZE0

M SIZE1

 

M FREF

 

 

M SPD0

M SPD1

 

R A TYP0

R A TYP1

R A TYP2

 

R B TYP0

R B TYP1

R B TYP2

L2 TYPE0

L2 TYPE1

L2 TYP2

L3 TYPE3

L2 PLL0

L2 PLL1

L2 PLL2

L2 PLL3

 

 

FLSHP0

FLSHP1

FLSHP2-

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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]

Memory Size. This field is encoded as follows:

M_SIZE[0:1]

Total Memory On Board

 

 

0B00

16 Megabytes

 

 

0B01

32 Megabytes

 

 

0B10

64 Megabytes

 

 

0B11

128 Megabytes

 

 

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.

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Motorola MVME2300 Series manual Memory Configuration Register Memcr, MSIZE01, Memory Configuration Register $FEF80404