RM0444 Rev 5 1323/1390
RM0444 USB Type-C™ / USB Power Delivery interface (UCPD)
1346
By enabling bits TXDMAEN and/or RXDMAEN, DMA can be activated independently for Tx
and/or Rx functionality.
38.4.10 Wakeup from Stop mode
For power consumption optimization, it is useful to use Stop mode and wait for events on
CC lines to wake the MCU up.
In order for this to work, it must be first enabled by writing a 1 to WUPEN.
The events causing the wakeup can be:
• Events on the BMC receiver (RXORDDET, RXHRSTDET), hardware enable
PHYRXEN
• Event on the FRS detector (FRSEVT), hardware enable FRSRXEN
• Events on the Type-C detectors (TYPECEVT1, TYPECEVT2), hardware enables
CC1TCDIS, CC2TCDIS
38.4.11 UCPD programming sequences
The normal sequence of use of the UCPD unit is:
1. Configure UCPD.
2. Enable UCPD.
3. Concurrently:
– On demand from protocol layer, send Tx message
– Intercept (poll or wait for interrupt) relevant Rx messages and recover detail to
hand off to protocol layer
Repeat the last point infinitely.
Initialization phase
Use the following sequence for a clean startup:
1. Prepare all initial clock divider values, by writing the UCPD_CFG register.
2. Enable the unit, by setting the UCPDEN bit.
Type-C state machine handling
For the general application cases of source, sink, or dual-role port (the last alternating the
source and the sink), the software must implement a corresponding USB Type-C state
machine. The basic coding is in the following table.
Table 237. Coding for ANAMODE, ANASUBMODE and link with TYPEC_VSTATE_CCx
ANAMODE ANASUBMODE[1:0] Notes
TYPEC_VSTATE_CCx[1:0]
00 01 10 11
0: Source
00: Disabled Disabled N/A
01: Default USB Rp - vRa[Def] vRd[Def] vOPEN[Def]
N/A10: 1.5A Rp - vRa[1.5] vRd[1.5] vOPEN[1.5]
11: 3.0A Rp - vRa[3.0] vRd[3.0] vOPEN[3.0]
1: Sink xx - vRa vRd-USB vRd-1.5 vRd-3.0
To Next Page
Loading...
Need help?
General
