USB Type-C™ / USB Power Delivery interface (UCPD) RM0440
2052/2126 RM0440 Rev 4
The BIST test data packet frame format is shown in the following figure.
Figure 680. BIST test data frame
This is a fixed length test data pattern. In reality the only aspect that marks its difference
from the general packet format already shown in Figure 677: Packet format is the contents
of the Header. As UCPD receives the Tx Header contents via programming (it is simply
viewed as part of the payload), it is only this programming (and not the block’s behaviour)
that differentiates the general packet from the BIST Test Data packet.
BIST Carrier Mode 2
When required, this BIST test mode sends an alternating pattern of 1010 that is continually
repeated. As this mode is intended for signal analysis it is stable condition with (in V1.0 of
the USB PD specification) no defined length. Starting from V1.1 of the USB PD
specification, the protocol layer defines a counter that indicates when to exit this mode.
The way to quit the infinite 1010 sequence (according to requirements of the USB PD
specification) is to disable the UCPD peripheral via the UCPDEN bit.
Figure 681. BIST Carrier Mode 2 frame
46.4.4 UCPD BMC transmitter
The BMC transmitter comprises 4b5b encoding, CRC generation, and BMC encode, as
shown in the following figure. Its output goes to the analog PHY through a channel switch.
MSv45542V2
Preamble
(training for receiver)
SOP*
(start of packet)
BIST test data
(192 bits)
Legend:
CRC
EOP
(end of packet)
...
Header
Data objects = 7
BIST Test Data
BDO
...
Provided by the physical layer, not 4b5b-encoded
Provided by the physical layer, 4b5b-encoded
Provided by the protocol layer, 4b5b-encoded
MSv45543V2
Preamble
(training for receiver)
SOP*
(start of packet)
Legend:
Provided by the physical layer, not 4b5b-encoded
Provided by the physical layer, 4b5b-encoded
10101010101010101010……
(repeated until UCPD is disabled)
UCPDEN = 0
To Next Page
Loading...
Need help?
General
