SM-B79
SM-B79 User Manual - Rev. First Edition: 1.0 - Last Edition: 1.0 - Author: A.R - Reviewed by M.B. - Copyright © 2021 SECO S.p.A.
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Since SM-B79 is a carrier board specifically designed for development purposes, onboard
there is a 4-way jumper to select normal working of HDMI/DP1++ interface or to fix this
To select standard mode working, the jumper must be set in 3-4 position.
3.3.6
DP0++ connector
According to SMARC
®
Rel. 2.1.1 specification, also the third display interface from card edge
connector can be used to implement multi-purpose Digital Display Interfaces. As stated in the
specification, the third display interface can support multimode display port, that can be either used as
DP++ interface or HDMI over DP++ through external dongle. The difference with second display
interface is that this one cannot support native HDMI, and this is the reason why there is not an high
speed multiplexer to redirect signals from card edge connector as per second display interface
(par.3.3.5)
Please notice that the effective support of this kind of displays depends only by the SMARC
®
module
used with the SM-B79 carrier board, it is not a feature dependent from the carrier board itself.
The pin-out of this card edge connector is given according to SMARC
®
Rel. 2.1.1 specifications, so
that the carrier board is ready for the use of any SMARC
®
module that follows those specifications.
Please refer to the SMARC
®
the availability of the HDMI / DP++ signals.
The multimode Display Port interface (DP0++) from card edge connector
is made available on connector CN74, type WINNING p/n WDPE-
20F3L1BU3 or equivalent, with the pinout shown in the left table.
Signal Description:
DDI/DDI0_PAIR0-: SMARC
®
module DDI Interface #0 Differential Pair #0. Can be used as Display Port differential pair #0 or TMDS (HDMI) differential pair
#2
DDI/DDI0_PAIR1-: SMARC
®
module DDI Interface #0 Differential Pair #1. Can be used as Display Port differential pair #1 or TMDS (HDMI) differential pair
#1
DDI/DDI0_PAIR2-: SMARC
®
module DDI Interface #0 Differential Pair #2. Can be used as Display Port differential pair #2 or TMDS (HDMI) differential pair
#0
DDI/DDI0_PAIR3-: SMARC
®
module DDI Interface #0 Differential Pair #3. Can be used as Display Port differential pair #3 or TMDS (HDMI) Clock differential
pair
CN76 position DP1++ Working mode
1-3
Fixed HDMI mode (DDC available)
3-4
Multimode DP (standard working)
3-5
Fixed DP mode (DP_AUX available)
Multimode DP#0 Connector CN74
Pin Signal
Pin Signal
1
DDI
2
GND
3
DDI0_PAIR0-
4
DDI
5
GND
6
DDI0_PAIR1-
7
DDI
8
GND
9
DDI0_PAIR2-
10
DDI
11
GND
12
DDI0_PAIR3-
13
DDI0_DDC_AUX_SEL
14
DDI0_CEC
15
DDI0_CTRL
16
GND
17
DDI0_CTRLDATA_AUX-
18
DDI0_HPD
19
GND
20
DD0_PWR