Dram base register, Clk frequency register, Dram base register -35 clk frequency register -35 – Motorola MVME2300 Series User Manual

Page 197

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3-35

3

DRAM Base Register

RAM A/B/C/D BASE

These control bits define the base address for their block’s
DRAM. RAM A/B/C/D BASE bits 0-7/8-15/16-23/24-
31 correspond to PowerPC 60x address bits 0 - 7. For
larger DRAM sizes, the lower significant bits of A/B/C/D
BASE
are ignored. This means that the block’s base
address will always appear at an even multiple of its size.
Note that bit 0 is MSB.

Also note that the combination of RAM_X_BASE and
ram_x_siz should never be programmed such that
DRAM responds at the same address as the CSR,
ROM/Flash, External Register Set, or any other slave on
the PowerPC bus.

CLK Frequency Register

CLK FREQUENCY

These bits should be programmed with the hexadecimal
value of the operating CLOCK frequency in MHz (i.e.
$42 for 66MHz). When these bits are programmed this
way, the chip’s prescale counter produces a 1MHz output.

Address

$FEF80018

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

RAM A BASE

RAM B BASE

RAM C BASE

RAM D BASE

Operation

READ/WRITE

READ/WRITE

READ/WRITE

READ/WRITE

Reset

0 PL

0 PL

0 PL

0 PL

Address

$FEF80020

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

CLK

FREQUENCY

0

0

0

0

0

0

0

po
r

Operation

READ/WRITE

READ ZERO

READ ZERO

R

R

R

R

R

R

R

R/
C

Reset

42 P

X

X

X

X

X

X

X

X

X

1 P

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