USB Connectivity
1655
SPNU503C – March 2018
Copyright © 2018, Texas Instruments Incorporated
Universal Serial Bus (USB)
29.4.3 Transceiver Signaling
The USB module on this device uses a unidirectional (6-wire) signaling type for the transceiver. The
signaling is shown in
.
Table 29-57. Signaling Between USB Controller and Unidirectional USB Transceiver Using
DAT/SE0 Signaling
Logical Signal
Name(s)
Pin Direction
Transceiver Pin
Direction
Description
GZO
Output
Input
When low, USB transceiver drives D+ and D-.
DAT and SE0
Output
Input
Controls the values output by the USB transceiver on D+ and D-
when GZO is low. Ignored when GZO is high.
GZO
DAT
SE0
D+
D-
0
0
0
0
1
1
0
1
0
X
1
0
0
1
X
X
Undriven
Undriven
RCV
Input
Output
Output from transceiver differential receiver.
D+
D-
RCV
0
0
X
0
1
0
1
0
1
1
1
X
VP
Input
Output
Output from transceiver single-ended D+ signal receiver .
D+
VP
0
0
1
1
VM
Input
Output
Output from transceiver single-ended D- signal receiver.
D-
VM
0
0
1
1
SPEED
Output
Input
Determines transceiver D+, D- output characteristics.
0 = Low speed.
1 = Full speed.
Transceivers with I
2
C interfaces can implement this functionality as a
control bit rather than a pin.
SUSPEND
Output
Input
Controls transceiver power down modes.
0 = Active mode.
1 = Low-power mode.
Transceivers with I
2
C interfaces can implement this functionality as a
control bit rather than a pin.
This device does not support unidirectional transceivers that implement VPO/VMO signaling.