Vmebus Timing; Table 5-2. Vmebus Timing - RadiSys EPC - 6A Hardware Reference Manual

VMEbus Timing

The following table contains some illustrations of the duration of VMEbus operations.
The times were measured with the EPC-6A in the ROR bus-release mode.
Operation
Fill VMEbus slave memory, each iteration of
REP,STOSW instructions
Move block of local memory to VMEbus slave
memory, each iteration of REP,MOVSW
instructions
Move block of VMEbus slave memory to local
memory, each iteration of REP,MOVSW
instructions
Write access from another master to the
EPC-6A's DRAM
Read access from another master to the
EPC-6A's DRAM
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Chapter 5: Theory of Operation

Table 5-2. VMEbus timing

Time
300 ns + DS-DTACK slave's write access time
400 ns + the greater of:
50 ns
slave's DS-DTACK write access time
650 ns + DS-DTACK slave's read access time
DS-DTACK time = 325 ns+ HI
HI is hold-interference time, can range from 0
to 15000 ns, typically is 150 ns
DS-DTACK time = 450 ns + HI
HI as defined above
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