USB3320C-EZK-TR Datasheet, PDF (24/82 Pages) Microchip Technology – Highly Integrated Full Featured Hi-Speed USB 2.0 ULPI Transceiver

5.2.2
Highly Integrated Full Featured Hi-Speed USB 2.0 ULPI Transceiver
Datasheet
it may be desirable to compensate for loss by adjusting the HS transmitter amplitude. The Boost bits
in the HS TX Boost register may be configured to adjust the HS transmitter amplitude at the DP and
DM pins.
Termination Resistors
The USB3320 transceiver fully integrates all of the USB termination resistors on both DP and DM. This
includes 1.5kΩ pull-up resistors, 15kΩ pull-down resistors and the 45Ω high speed termination
resistors. These resistors require no tuning or trimming by the Link. The state of the resistors is
determined by the operating mode of the transceiver when operating in synchronous mode.
The XcvrSelect[1:0], TermSelect and OpMode[1:0] bits in the Function Control register, and the
DpPulldown and DmPulldown bits in the OTG Control register control the configuration. The possible
valid resistor combinations are shown in Table 5.1, and operation is guaranteed in only the
configurations shown. If a ULPI Register Setting is configured that does not match a setting in the
table, the transceiver operation is not guaranteed and the settings in the last row of Table 5.1 will be
used.
„ RPU_DP_EN activates the 1.5kΩ DP pull-up resistor
„ RPU_DM_EN activates the 1.5kΩ DM pull-up resistor
„ RPD_DP_EN activates the 15kΩ DP pull-down resistor
„ RPD_DM_EN activates the 15kΩ DM pull-down resistor
„ HSTERM_EN activates the 45Ω DP and DM high speed termination resistors
The USB3320 also includes two DP and DM pull-up resistors described in Section 5.8.
Table 5.1 DP/DM Termination vs. Signaling Mode
ULPI REGISTER SETTINGS
USB3320 TERMINATION
RESISTOR SETTINGS
SIGNALING MODE
General Settings
Tri-State Drivers
Power-up or VBUS < V_SESSEND
Host Settings
Host Chirp
Host Hi-Speed
Host Full Speed
Host HS/FS Suspend
Host HS/FS Resume
Host low Speed
Host LS Suspend
Revision 1.0 (07-14-09)
XXb Xb 01b Xb Xb 0b 0b 0b 0b 0b
01b 0b 00b 1b 1b 0b 0b 1b 1b 0b
00b 0b 10b 1b 1b 0b 0b 1b 1b 1b
00b 0b 00b 1b 1b 0b 0b 1b 1b 1b
X1b 1b 00b 1b 1b 0b 0b 1b 1b 0b
01b 1b 00b 1b 1b 0b 0b 1b 1b 0b
01b 1b 10b 1b 1b 0b 0b 1b 1b 0b
10b 1b 00b 1b 1b 0b 0b 1b 1b 0b
10b 1b 00b 1b 1b 0b 0b 1b 1b 0b
24
DATASHEET
SMSC USB3320