Datasheet

Highly Integrated Full Featured Hi-Speed USB 2.0 ULPI Transceiver
Datasheet
SMSC USB3320 45 Revision 1.0 (07-14-09)
DATASHEET
6.2.1 ULPI Register Write
A ULPI register write operation is given in Figure 6.3. The TXD command with a register write
DATA[7:6] = 10b is driven by the Link at T0. The register address is encoded into DATA[5:0] of the
TXD CMD byte.
To write a register, the Link will wait until DIR is low, and at T0, drive the TXD CMD on the data bus.
At T2 the transceiver will drive NXT high. On the next rising clock edge, T3, the Link will write the
Table 6.2 ULPI TXD CMD Byte Encoding
COMMAND NAME
CMD
BITS[7:6] CMD BITS[5:0] COMMAND DESCRIPTION
Idle 00b 000000b ULPI Idle
Transmit 01b 000000b USB Transmit Packet with No Packet Identifier
(NOPID)
00XXXXb USB Transmit Packet Identifier (PID) where DATA[3:0]
is equal to the 4-bit PID. P
3
P
2
P
1
P
0
where P
3
is the
MSB.
Register Write 10b XXXXXXb Immediate Register Write Command where:
DATA[5:0] = 6-bit register address
101111b Extended Register Write Command where the 8-bit
register address is available on the next cycle.
Register Read 11b XXXXXXb Immediate Register Read Command where:
DATA[5:0] = 6-bit register address
101111b Extended Register Read Command where the 8-bit
register address is available on the next cycle.
Figure 6.3 ULPI Register Write in Synchronous Mode
DIR
CLK
DATA[7:0]
STP
NXT
TXD CMD
(reg write)
Idle Reg Data[n] Idle
ULPI Register
Reg Data [n-1] Reg Data [n]
T0 T1 T2 T3 T5T4 T6