Digi NS9750 - Manual (Page 855)

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T i m i n g
IEEE 1284 timing
Note:
All AC characteristics are measured with 10pF, unless otherwise noted.
Table 476 describes the values shown in the IEEE 1284 timing diagram (Figure 140).
Notes:
1 The range is 0ns up to one time unit.
2 Two time units.
3 Three time units.
IEEE 1284 timing example
The IEEE 1284 timing is determined by the BBus clock and the Granularity Count
register (GCR) setting. In this example, the BBus clock is 50 MHz and the Granularity
Count register is set to 25. The basic time unit is
1/50 MHz x 25
, which is 500ns.
Figure 140: IEEE 1284 timing with BBus clock at 50 MHZ and GCR set to 25
Parm Description Min Max Unit Note
IE1 Busy-while-Strobe 0 500 ns 1
IE2 Busy high to nAck low 0 ns
IE3 Busy high 1000 ns 2
IE4 nAck low 500 ns 3
IE5 nAck high to Busy low 500 ns 3
Table 476: IEEE 1284 timing parameters
IE1
IE3
IE5
IE2
IE4
Data[8:1]
nStrobe
Busy
nAck