cbtl12131 NXP Semiconductors, cbtl12131 Datasheet - Page 11

• Manufacturer Part Number: cbtl12131
• Description: Cbtl12131 Displayport Multiplexer For Bidirectional Video In All-in-one Computer Systems
• Manufacturer: NXP Semiconductors

NXP Semiconductors
CBTL12131
Product data sheet
Fig 6.
HPD_B_FLT = 1 and PATH_SEL = 0 and DDC_AUX_SEL = 0: pass
HPD_B_FLT = 1 and PATH_SEL = 0 and DDC_AUX_SEL = 1: pass
AUX and DDC channel topology
7.3 AUX and DDC switches/multiplexers
For all ports except Port A, only a single pair of signal lines is provided. The path
configuration for the AUX/DDC channels follows that of the Main Link: when
PATH_SEL = LOW, Ports C and D are connected; when PATH_SEL = LOW and
HPD_B_FLT = HIGH, also Ports A and B are connected; when PATH_SEL = HIGH,
Port D is connected to Port B, and Ports A and C are isolated (see
Port A additionally provides a second pair of signal lines, to allow bypassing of external
AC-coupling capacitors (normally placed in series with the AUX channel) in the case when
an external ++DP cable adapter is detected, and therefore a DC path needs to be
provided from the external DP connector’s AUX_P and AUX_N lines, in order to support
DDC communication across those lines between the External Graphics GPU (facing
Port A) and the external ++DP cable adapter. Selection between the DDC and AUX
channels of Port A is determined by the input DDC_AUX_SEL: when
DDC_AUX_SEL = LOW, the active channel is AUX_A; when DDC_AUX_SEL = HIGH,
the active channel is DDC_A. Typically, DDC_AUX_SEL is driven by a qualified version of
the DP ‘Cable Detect’ signal (pin 4 of a miniDP connector or pin 13 of a normal DP
connector) and will be HIGH when such a cable adaptor is connected and powered.
All information provided in this document is subject to legal disclaimers.
select between
AUX and DDC
Rev. 1 — 25 February 2011
PATH_SEL = 0: pass
PATH_SEL = 1: off
DDC_A
AUX_C
AUX_A
else: off
else: off
DisplayPort multiplexer for bidirectional video
PATH_SEL = 0: off
PATH_SEL = 1: pass
CBTL12131
Figure
© NXP B.V. 2011. All rights reserved.
002aae678
6).
AUX_D
AUX_B
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