J1850 vpw passive symbols -22 – Freescale Semiconductor MPC5200B User Manual

Page 701

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MPC5200B Users Guide, Rev. 1

20-22

Freescale Semiconductor

Functional Description

The min and max symbol limits shown in the following sections (Invalid Passive Bit - Valid BREAK Symbol) and figures (

Figure 20-6

-

Figure 20-9

) refer to the values listed in

Table 20-13

through

Table 20-18

.

Invalid Passive Bit

If the passive to active transition beginning the next data bit or symbol occurs between the active to passive transition beginning the
current data bit or symbol and T

rvp1(Min)

, the current bit would be invalid. See

Figure 20-6

(1).

Figure 20-6. J1850 VPW Passive Symbols

Valid Passive Logic Zero

If the passive to active transition beginning the next data bit or symbol occurs between T

rvp1(Min)

and T

rvp1(Max)

, the current bit

would be considered a logic zero. See

Figure 20-6

(2).

Valid Passive Logic One

If the passive to active transition beginning the next data bit or symbol occurs between T

rvp2(Min)

and T

rvp2(Max)

, the current bit

would be considered a logic one. See

Figure 20-6

(3).

Valid EOD Symbol

If the passive to active transition beginning the next data bit or symbol occurs between T

rvp3(Min)

and T

rvp3(Max)

, the current symbol

would be considered a valid EOD symbol. See

Figure 20-6

(4).

T

rvp1(Min)

T

rvp2(Min)

T

rvp2(Max)

T

rvp1(Max)

T

rvp1(Min)

(1) Invalid Passive

(2) Valid Passive

(3) Valid Passive

64

µs

128

µs

T

rvp3(Min)

T

rvp3(Max)

(4) Valid EOD

Symbol

Logic One

Bit

Logic Zero

200

µs

Active

Passive

Active

Passive

Active

Passive

Active

Passive

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