3

Falcon ECC Memory Controller Chip Set

ROM B Base/Size Register

Address

 

 

 

 

 

 

 

 

 

 

 

 

 

 

$FEF80058

 

 

 

 

 

 

 

 

 

 

 

 

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

 

 

 

ROM B BASE

 

 

rom_b

rom b

 

rom b

rom b

 

 

 

 

 

 

 

 

0

0

0

0

0

 

rom_b

 

rom b

 

rom b

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

_64

siz0

 

siz1

siz2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

_rv

 

en

 

we

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Operation

 

 

 

READ/WRITE

 

 

R

R/W

 

R/W

R/W

 

READ ZERO

 

R

R

R

R

R

R/W

R/W

R/W

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset

 

 

 

 

$FF4 PL

 

 

V

0

 

0

0

 

 

 

 

 

 

 

 

X

X

X

X

X

V

0

0

 

 

 

 

 

 

 

 

 

 

 

 

 

P

PL

 

PL

PL

 

 

 

X

 

 

 

 

 

 

P

PL

PL

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ROM B BASE

These control bits define the base address for ROM/Flash Block B. ROM B BASE bits 0-11 correspond to PowerPC 60x address bits 0-11 respectively. For larger ROM/Flash sizes, the lower significant bits of ROM B BASE are ignored. This means that the block’s base address will always appear at an even multiple of its size. ROM B BASE is initialized to $FF4 at power-up or local bus reset.

Note that in addition to the programmed address, the first

1Mbyte of Block B also appears at $FFF00000 -

$FFFFFFFF if the rom_b_rv bit is set.

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

rom_b_64

rom_b_64 indicates the width of the ROM/Flash device(s) being used for block B. When rom_b_64 is cleared, block B is 16 bits wide, where each Falcon interfaces to 8 bits. When rom_b_64 is set, block B is 64 bits wide, where each Falcon interfaces to 32 bits.

3-48

Computer Group Literature Center Web Site

Page 210
Image 210
Motorola MVME2300 Series manual ROM B Base/Size Register, 1Mbyte of Block B also appears at $FFF00000