Motorola MVME2400 - Manual (Page 68)

3-20 Computer Group Literature Center Web Site
Functional Description
3
Note: The information in Table 3-10 is appropriate when configured with
devices with an access time equal to 12 CLK periods.
Note: The information in Table 3-11 is appropriate when configured with
devices with an access time equal to 8 CLK periods.
Table 3-10. PPC Bus to ROM/Flash Access Timing (120ns @ 100MHz)
ACCESS TYPE
CLOCK PERIODS REQUIRED FOR:
Total
Clocks
1st Beat 2nd Beat 3rd Beat 4th Beat
16
Bits
64
Bits
16
Bits
64
Bits
16
Bits
64
Bits
16
Bits
64
Bits
16
Bits
64
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
Table 3-11. PPC Bus to ROM/Flash Access Timing (80ns @ 100MHz)
ACCESS TYPE
CLOCK PERIODS REQUIRED FOR:
Total
Clocks
1st Beat 2nd Beat 3rd Beat 4th Beat
16
Bits
64
Bits
16
Bits
64
Bits
16
Bits
64
Bits
16
Bits
64
Bits
16
Bits
64
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