Datasheet

SN75DP130
SLLSE57D –APRIL 2011–REVISED JULY 2013 www.ti.com
Table 2. Description of SN75DP130 Operating Modes
MODE CHARACTERISTICS CONDITIONS
Least amount of power consumption (most circuitry turned off); HPD_SRC
reflects HPD_SNK state; all other outputs are high-impedance; if RSTN is high
EN or RSTN is low;
Shutdown Mode local I
2
C IF remains active; if RSTN is low local I
2
C interface is turned off, all
Power on default mode
other inputs are ignored, and AUX DPCD is reset. (EN=low does not reset
DPCD)
Low power consumption (I
2
C IF is active; AUX monitor is inactive); Main Link EN and RSTN are high;
Standby Mode
outputs are disabled;
HPD_SNK low longer than t
T(HPD)
Low power consumption (I
2
C IF is active; AUX monitor active in DP mode); Main EN and RSTN are high;
D3 Power Down
Link outputs are disabled;
AUX cmd requested DP sink to
Mode
enter D3 power saving mode
Data transfer (normal operation); The device is either in TMDS mode
(CAD_SNK=high) or DP mode (CAD_SNK=low);
In DP mode, the AUX monitor is actively monitoring for Link Training; the output
EN and RSTN are high;
signal swing and input equalization setting depend on the Link Training or I
2
C
HPD_SNK is high;
settings; the AUX SRC channel is active; the AUX SNK and DDC are active
Active Mode unless disabled through I
2
C IF. At power-up all Main Link outputs are disabled by
HPD_SNK can also be low for less
default. AUX Link Training is necessary to overwrite the DPCD registers to
than t
Z(HPD)
(e.g., sink interrupt
enable Main Link outputs.
request to source)
In TMDS mode the output signal swing is 600mVpp unless this setting is adjusted
by overwriting according registers through I
2
C IF. Transactions on the AUX lines
will be ignored.
Through I
2
C registers the device can be forced into ignoring HPD_SNK and
Compliance Test CAD_SNK, HPD_SRC and CAD_SRC are programmable; output swing, pre- EN and RSTN is high; I
2
C selects
Mode emphasis and EQ setting are programmable; automatic power down features can HPD and/or CAD test mode
be disabled
DPCD write commands on the AUX bus detected by the SN75DP130 will also
write to the local DPCD register. The DPCD register should always be written
EN and RSTN are high;
with a valid entry. If register 101h or 103h is written with a forbidden value, the
Output Disable
SN75DP130 disables the Main Link output signals, forcing the DP sink to issue
DPCD register 101h or 103h entry is
Mode
an interrupt. The DP source can now re-train the link using valued DPCD register
invalid
values. As soon as all DPCD registers contain a valid entry, the SN75DP130
switches back into the appropriate mode of operation.
Table 3. Description of Operating Mode Transitions
MODE TRANSITION USE CASE TRANSITION SPECIFICS
Shutdown → Standby Activate SN75DP130 EN and RSTN both transitioned high
Standby → Active Turn on Main Link (DP sink plugged in) HPD_SNK input asserts high
DP source requests temporary power down for
Active → D3 Power Down Receive D3 entry command on AUX
power savings
Active → Output Disable Squelch event; inactive video stream Main Link monitor detects the inactive video stream
Receive D3 exit command on AUX, or CAD_SNK
D3 Power Down → Active Exit temporary power down
input is asserted (high)
D3 Power Down → Standby Exit temporary power down (DP sink unplugged) HPD_SNK de-asserted to low for longer than t
T(HPD)
Active → Standby Turn off Main Link (DP sink unplugged) HPD_SNK de-asserted to low for longer than t
T(HPD)
Any → Shutdown Turn off SN75DP130 EN or RSTN transitions low
Any → Output Disable DPCD register access error condition Invalid DPCD register access
Output Disable → Active Squelch released; video stream re-activated Main Link monitor detects active video stream
Output Disable → Any DPCD register error condition is corrected Appropriate operating mode is re-entered
IMPLEMENTING THE RSTN SIGNAL
The SN75DP130 RSTN input gives control over the device reset and to place the device into shut-down mode.
When RSTN is low, all DPCD registers are reset to their default values, and all Main Link lanes are disabled.
When the RSTN input returns to a high logic level, the device comes out of the Shutdown mode. To turn on the
Main Link, it is necessary to either program the DPCD registers through the local I
2
C interface or to go through a
full sequence of Link Training between DP source and DP sink.
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