P9222-R/RN Datasheet

© 2019-2022 Renesas Electronics Corporation

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May 5, 2022

Figure 17. Timing Diagram for a User Data Transfer from the P9222-R/RN to the P9235-RB

The P9222-R/RN transfers data into the channel at a speed of 2Kbps. However, the channel is usually busy transmitting WPC standard

communication packets. There is a very small window in which the user data can be transferred. Typically in the power transfer phase, the CEP

packet is sent every 150msec. In one second, there will be only 6 to 7 time slots in which the P9222-R/RN can send a maximum of 7 bytes

(including the checksum and header) of user data in each slot. The maximum data transfer rate achieved between the P9222-R/RN and the

P9235-RB is 100bps. The P9222-R/RN will reset bit 0 in the Command register 0x4E to 0 immediately after sending the data into the channel.

The external MCU on the receiver can periodically check bit 0 in the P9222-R/RN register 0x4E to get an acknowledgment of successful data

transmission into the channel.

Note: The P9222-R/RN gives WPC standard communication packets priority over user data packets. User data packets have the lowest priority;

therefore, during load transients, the P9222-R/RN may skip sending user data packets and give priority to CEP and indicate the channel status

as busy in register 0x4E. The P9222-R/RN does not wait for acknowledgement from the P9235-RB or keep track of successful delivery of the

data to the P9235-RB. The P9222-R/RN only functions as a messenger and relies on the external MCUs on the receiver and transmitter boards

to create a lossless communication protocol by adding intelligence into data they are transferring.

Figure 18. Typical P9222-R/RN to P9235-RB Data Transfer using the P9235A-RB-EVK Evaluation Kit

Note: The P9235A-RB-EVK is the evaluation kit available for the P9222-R/RN and P9235-RB, which implements the typical application

schematic shown in Figure 32.