Functional Description

3

Table 3-10. PPC Bus to ROM/Flash Access Timing (120ns @ 100MHz)

 

 

CLOCK PERIODS REQUIRED FOR:

 

Total

 

 

 

 

 

 

 

 

 

ACCESS TYPE

1st Beat

2nd Beat

3rd Beat

4th Beat

Clocks

 

 

 

 

 

 

 

 

 

 

 

 

 

16

64

16

64

16

64

16

64

16

64

 

Bits

Bits

Bits

Bits

Bits

Bits

Bits

Bits

Bits

Bits

 

 

 

 

 

 

 

 

 

 

 

4-Beat Read

70

22

64

16

64

16

64

16

262

70

 

 

 

 

 

 

 

 

 

 

 

4-Beat Write

 

 

 

N/A

 

 

 

N/A

 

 

 

 

 

 

 

 

 

 

 

1-Beat Read (1 byte)

22

22

-

-

-

-

-

-

22

22

 

 

 

 

 

 

 

 

 

 

 

1-Beat Read (2 to 8 bytes)

70

22

-

-

-

-

-

-

70

22

 

 

 

 

 

 

 

 

 

 

 

1-Beat Write

21

21

-

-

-

-

-

-

21

21

 

 

 

 

 

 

 

 

 

 

 

Note: The information in Table 3-10 is appropriate when configured with devices with an access time equal to 12 CLK periods.

Table 3-11. PPC Bus to ROM/Flash Access Timing (80ns @ 100MHz)

 

 

CLOCK PERIODS REQUIRED FOR:

 

Total

 

 

 

 

 

 

 

 

 

ACCESS TYPE

1st Beat

2nd Beat

3rd Beat

4th Beat

Clocks

 

 

 

 

 

 

 

 

 

 

 

 

 

16

64

16

64

16

64

16

64

16

64

 

Bits

Bits

Bits

Bits

Bits

Bits

Bits

Bits

Bits

Bits

 

 

 

 

 

 

 

 

 

 

 

4-Beat Read

54

18

48

12

48

12

48

12

198

54

 

 

 

 

 

 

 

 

 

 

 

4-Beat Write

N/A

 

 

 

 

 

 

 

N/A

 

 

 

 

 

 

 

 

 

 

 

 

1-Beat Read (1 byte)

18

18

-

-

-

-

-

-

18

18

 

 

 

 

 

 

 

 

 

 

 

1-Beat Read (2 to 8 bytes)

54

18

-

-

-

-

-

-

54

18

 

 

 

 

 

 

 

 

 

 

 

1-Beat Write

21

21

-

-

-

-

-

-

21

21

 

 

 

 

 

 

 

 

 

 

 

Note: The information in Table 3-11 is appropriate when configured with devices with an access time equal to 8 CLK periods.

3-20

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Motorola MVME2400 manual Total, 1st Beat 2nd Beat 3rd Beat 4th Beat Clocks Bits