UPSD3234AV-24U1T STMicroelectronics, UPSD3234AV-24U1T Datasheet - Page 79

• Manufacturer Part Number: UPSD3234AV-24U1T
• Description: Flash Programmable System Devices with 8032 Microcontroller Core and 64Kbit SRAM
• Manufacturer: STMicroelectronics

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Host Type Detection
The detection procedure conforms to the se-
quences proposed by VESA Monitor Display Data
Channel (DDC) specification. The monitor needs
to determine the type of host system:
Figure 41. Host Type Detection
Power on
EDID sent continously using
Is VSYNC present?
Stop sending of EDID
communication mode
DDC2B command
uPSD3234A, uPSD3234BV, uPSD3233B, uPSD3233BV
Is it DDC2B
command?
VSYNC as clock
Is DDC2 clock
switch to DDC2
Communication
Respond to
present?
isidle
DDC1 or OLD type host.
DDC2B host (Host is master, monitor is
always slave)
DDC2B+/DDC2AB(ACCESS.bus) host.
command detected?
DDC2B+/DDC2AB?
DDC2 communication
Has a command
Respond to DDC2B+/
DDC2AB command
been received?
Is 2B+/A.B
is idle.
Is
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