Intel 87C196CA, Supplement To User’S Manual

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8-11
J1850 COMMUNICATIONS CONTROLLER
Figure 8-8. Definition for Start and End of Frame Symbols
Table 8-4 details the symbol timing characteristics supported by the 87C196LB.
Table 8-4. Huntzicker Symbol Timing Characteristics
Name Symbol Bus Level T
TX
min T
TX
nom T
TX
max T
RX
min T
RX
max Units
Logic Level 0 0
Passive 60 64 68 34 <96 µs
Active 122 128 134 96 <163 µs
Logic Level 1 1
Passive 122 128 134 96 <163 µs
Active 60 64 68 34 <96 µs
Start of Frame SOF Active 193 200 207 163 <239 µs
End of Data EOD Passive 193 200 207 163 <239 µs
End of Frame EOF Passive 271 280 289 239 <300 µs
In-frame Separation IFS Passive >300 — — >300 — µs
Break BRK Active 768 — — >239 — µs
NOTE: Timings are based on the standard bus rate of 10.4 Kb/s. When operating in 4x mode, the bus
rate becomes 41.6 Kb/s and all symbol timings are one fourth that shown.
A5221-01
0
1
0
1
"Break Signal (BRK)"
"In-frame Separation (IFS)"
300µS+
0
1
200µS
0
1
"End of Frame (EOF)"
280µS
0
1
768µS+
200µS
"Start of Frame (SOF)"
"End of Data (EOD)"