THine THCV245 A, Руководство пользователя

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Preliminary
THCV245A_Rev.0.90_E
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6.4 HTPDN/LOCKN
Hot-Plug Function
HTPDN indicates Main-Link connect condition between Transmitter and Receiver. HTPDN of Transmitter side
is high when Receiver is not active or not connected. Then Transmitter can enter into power down mode. HTPDN
is set to Low by the Receiver when Receiver is active and connects to the Transmitter, and then Transmitter must
start up and transmit CDR training pattern for link training. HTPDN is open drain output at the receiver side.
Transmitter side needs Pull-up resistor.
There is an application option to omit HTPDN connection between Transmitter and Receiver. In this case,
HTPDN at Transmitter side should always be at Low.
Lock Detect Function
LOCKN indicates whether CDR PLL of Main-Link is in lock status or not. LOCKN at Transmitter input is set
to High by pull-up resistor when Receiver is not active or in CDR PLL training. LOCKN is set to Low by Receiver
when CDR lock is completed. After that the CDR training mode finishes and then Transmitter shifts to the normal
mode. LOCKN of Receiver is open drain. Transmitter side needs pull-up resistor.
When an application omits HTPDN, LOCKN signal should only be considered with HTPDN pulled low by
Receiver.
Vcc
(Tx side)
MSSEL
(HTPDN)
LOCKN
THCV241A
3
0
k
Ω
HTPDN
LOCKN
3
0
k
Ω
Vcc
(Tx side)
MSSEL
(HTPDN)
LOCKN
THCV241A
HTPDN
LOCKN
V-by-One®
HS Rx
3
0
k
Ω
With HTPDN connect Without HTPDN connect
V-by-One®
HS Rx
Figure 3. Physical wire connection for wired Hot-plug and Lock detect scheme
It will need same GND potential reference between transmitter and receiver device to connect HTPDN and
LOCKN pins directly like above. HTPDN and LOCKN can also be transmitted via Sub-Link without physical
wire connection. Assignment can be configurable by 2-wire access to internal register.
Table 2. HTPDN/LOCKN register
Addr(h) Bits Register w idth R/W Description Default
0x101D [1:0] R_HTPDN_SEL 2 R/W
V-by-One® HS HTPDN assignment
00:Sub-Link at PDN1=1 / HTPDN pin input at PDN1=0,
01:Reserved,
10:forced Low
(Must be set at V-by -One® HS Distribution Enable)
,
11:forced High
2'h0
0x101E [5:4] R_LOCKN0_SEL 2 R/W
V-by-One® HS LOCKN for lane0 assignment
00:Sub-Link, 01:LOCKN pin input, 10:forced Low , 11:forced High
2'h0
0x101E [1:0] R_LOCKN1_SEL 2 R/W
V-by-One® HS LOCKN for lane1 assignment
00:Sub-Link, 01:LOCKN pin input, 10:forced Low , 11:forced High
2'h0
THCV245A THCV245A