3

Falcon ECC Memory Controller Chip Set

ROM/Flash Speeds

The Falcon pair provides the interface for two blocks of ROM/Flash. Each block can address up to 64MB of memory depending on the width implemented for that block (16 bits or 64 bits). Bank A is 64 bits wide and bank B is 16 bits wide. The access times for ROM/Flash are listed in Table 3-5and Table 3-6.

Table 3-5. PowerPC 60x Bus to ROM/Flash Access Timing — 64 Bits (32 Bits per Falcon)

 

 

Clock Periods Required For:

 

Total

Access Type

 

 

 

 

 

 

1st

 

2nd

3rd

 

4th

 

 

Clocks

 

 

 

 

Beat

 

Beat

Beat

 

Beat

 

 

 

 

 

 

 

 

 

4-Beat Read

20

 

16

16

 

16

68

 

 

 

 

 

 

 

 

4-Beat Write

N/A

 

N/A

N/A

 

N/A

N/A

 

 

 

 

 

 

 

 

1-Beat Read

20

 

-

-

 

-

20

 

 

 

 

 

 

 

 

1-Beat Write

19

 

-

-

 

-

19

 

 

 

 

 

 

 

 

Table 3-6. PowerPC 60x Bus to ROM/Flash Access Timing — 16 Bits (8 Bits

per Falcon)

 

 

Clock Periods Required For:

 

Total

Access Type

 

 

 

 

 

 

1st

 

2nd

3rd

 

4th

 

 

Clocks

 

 

 

 

Beat

 

Beat

Beat

 

Beat

 

 

 

 

 

 

 

 

 

4-Beat Read

68

 

64

64

 

64

260

 

 

 

 

 

 

 

 

4-Beat Write

N/A

 

N/A

N/A

 

N/A

N/A

 

 

 

 

 

 

 

 

1-Beat Read (2 bytes to 8 bytes)

68

 

-

-

 

-

68

 

 

 

 

 

 

 

 

1-Beat Read (1 byte)

20

 

-

-

 

-

20

 

 

 

 

 

 

 

 

1-Beat Write

19

 

-

-

 

-

19

 

 

 

 

 

 

 

 

3-10

Computer Group Literature Center Web Site

Page 172
Image 172
Motorola MVME2300 Series manual ROM/Flash Speeds