Datasheet

 2014-2016 Microchip Technology Inc. DS00001792E-page 47
USB3320
After the CarkitMode bit is set, the ULPI interface will become redefined as described in Table 6-8, and the USB3320
will transmit data through the DATA[0] to DM of the USB connector and receive data on DP and pass the information
the Link on DATA[1].
When entering UART mode, the regulator output will automatically switch to the value configured by the UART RegOut-
put bits in the USB IO & Power Management register and a pull-up will be applied internally to DP and DM. This will hold
the UART in its default operating state.
While in UART mode, the transmit edge rates can be set to either the Full Speed USB or Low Speed USB edge rates
by using the XcvrSelect[1:0] bits in the Function Control register.
6.5.2 USB AUDIO MODE
When the USB3320 is powered in Synchronous Mode, the Audio switches can be enabled by asserting the SpkLeftEn,
or SpkRightEn bits in the Carkit Control register. After the register write is complete, the USB3320 will immediately
enable or disable the audio switch. Then the Link can set the CarkitMode bit in the Interface Control register. The
SpkLeftEn, or SpkRightEn bits must be written before the CarkitMode bit.
After the CarkitMode bit is set, the ULPI interface will become redefined as described in Ta bl e 6 -8 .
6.6 RID Converter Operation
The RID converter is designed to read the value of the ID resistance to ground and report back its value through the
ULPI interface.
When a resistor to ground is applied to the ID pin the state of the IdGnd comparator will change from a 1 to a 0 as
described in Section 5.6.1. If the USB3320 is in ULPI mode, an RXCMD will be generated with bit 6 low. If the USB3320
is in Low Power Mode (or one of the other non-ULPI modes), the DATA[3] interrupt signal will go high.
TABLE 6-7: ULPI REGISTER PROGRAMMING EXAMPLE TO ENTER UART MODE
R/W
Address
(HEX)
Value
(HEX)
Description Result
W 04 49 Configure Non-Driving mode
Select FS transmit edge rates
OpMode=01
XcvrSelect=01
W 39 00 Set regulator to 3.3V UART RegOutput=00
W 19 0C Enable UART connections RxdEn=1
TxdEn=1
W 07 04 Enable carkit mode CarkitMode=1
TABLE 6-8: PIN DEFINITIONS IN CARKIT MODE
Signal Connected To Direction Description
txd DATA[0] IN UART TXD signal that is routed to the DM pin if the TxdEn
is set in the Carkit Control register.
rxd DATA[1] OUT UART RXD signal that is routed to the DP pin if the RxdEn
bit is set in the Carkit Control register.
reserved DATA[2] OUT Driven Low.
int DATA[3] OUT Asserted when any unmasked interrupt occurs. Active high.
reserved DATA[4:7] OUT Driven Low.
TABLE 6-9: ULPI REGISTER PROGRAMMING EXAMPLE TO ENTER AUDIO MODE
R/W
Address
(HEX)
Value
(HEX)
Description Result
W 04 48 Configure Non-Driving mode OpMode=01
W 19 30 Enable Audio connections SpkrRightEn=1, SpkrLeftEn=1
W 07 04 Enable carkit mode CarkitMode=1