MPC5777 DSPI Timed Serial Bus (TSB) mode

[huayeshen]

Hi NXP Team,

  I am using the MPC5777M . I am not sure what the DSPI module Timed Serial Bus (TSB) mode in the document . For example:
1.Is TSB used to achieve communication between one host and multiple slaves in DSI or DSI mode?

2.Do data frames and command frames in TSB mode refer to SPI frames and DSI frames, respectively?

3.I see that the selection bit of the command frame in TSB mode is "1", which is written through software. If the command frame is an SPI frame as mentioned in the second question, do I need to turn on the extended SPI mode to write additional selection bits?

Thanks

JAY LEEE

[davidtosenovjan · Accepted solution]

Timed Serial Bus (TSB) is a feature you may also see under the name Microsecond Bus (MSC). It is basically SPI communication protocol between MCU and power switch devices established in order to save general purpose output pins:

https://en.wikipedia.org/wiki/Microsecond_Bus

1) There is a dual receiver support, it means there may be used two slaves (two CSs). Pay attention to 49.5.9.1.

2) It is basically CSI mode - command frame is considered as SPI (SW way), data frame as DSI (serialized timer).

3) Not necessarily, it depends on the length of frame.

“The command frame can be written by software, through SPI TX FIFO, using one or two FIFO entries with help of the CONT bit or MCR[XSPI].”

[huayeshen]

Thank you very much for your answer. I'll go and take a closer look at the documentation.