AnsweredAssumed Answered

MPC5746 DSPI Extended Frame with continuous peripherial chip selection

Question asked by kupa harry on May 12, 2019
Latest reply on May 18, 2019 by kupa harry

Hello,DSPI module of MPC5746C supports extended frame, and i can receive and send multiple extended frames through DSPI.

But when i used the continuos selection format, it failed,the PCS port is not inactived after the last frame.

when i use the normal spi mode by setting xspi 0 with continuous selection format,i  can send multiple frames with the right wave of PCS,PCS port is active at the beginning of the first frame, and inactive at the end of the last frame.

I have noticed the datasheet,When transmitting multiple frames in this mode, the user software must ensure that
the last frame has the PUSHR[CONT] bit deasserted in Master mode.and I have done it.

In the 1338 page,the reference mentioned ,When Extended SPI Mode (MCR[XSPI]) is enabled, every CMD FIFO entry can have multiple TX FIFO entries attached to it. Thus a single CMD FIFO entry can be used to transmit multiple TX FIFO entries.

I have tried to deassert the PUSHER[CONT],but it falied. I want to know whether the extended frame support continuous selection format,and if it supports the feature ,then what should i do to inactivate the PCS port at the end of last frame? 

The figure3 displays extended frame tramission with continuous selection.

Outcomes