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Electrical Specifications
USB DC Electrical Characteristics
MC68HC908LD64 — Rev. 3.0
Data Sheet
Freescale Semiconductor
Electrical Specifications
353
24.12.4 USB Signaling Levels
Table 24-14. USB Signaling Levels
Bus State
Signaling Levels
From Originating Driver
At Receiver
Differential “1”
(D+) – (D–) > 200 mV and D+ or D– > VSE (min.)
Differential “0”
(D+) – (D–) < –200 mV and D+ or D– > VSE (min.)
Data J State:
Low Speed
Full Speed
Differential “0”
Differential “1”
Data K State:
Low Speed
Full Speed
Differential “1”
Differential “0”
Idle State:
Low Speed
Full Speed
Differential “0” and D– > VSE (max.) and D+ < VSE (min.)
Differential “1” and D+ > VSE (max.) and D– < VSE (min.)
Resume State:
Low Speed
Full Speed
Differential “1” and D+ > VSE (max.) and D– < VSE (min.)
Differential “0” and D– > VSE (max.) and D+ < VSE (min.)
Start of Packet (SOP)
Data lines switch from Idle to K State
End of Packet (EOP)
D+ and D– < VSE (min) for 2 bit
times(1) followed by an Idle for 1 bit
time
Notes:
1. The width of EOP is defined in bit times relative to the speed of transmission.
D+ and D– < VSE(min) for ≥ 1 bit
time(2) followed by a J State
2. The width of EOP is defined in bit times relative to the device type receiving the EOP.
Disconnect
(Upstream only)
—
D+ and D– < VSE(max) for ≥ 2.5 s
Connect
(Upstream only)
—
D+ or D– > VSE(max) for ≥ 2.5 s
Reset
(Downstream only)
D+ and D– < VSE for ≥10 ms
D+ and D– < VSE (min) for ≥ 2.5 s
(must be recognized within 5.5
s)(3)
3. These times apply to an active device that is not in the suspend state.