how to use uarte in 1M baud. RXD.AMOUNT will not update until fill up rxbuffer?



development kit:window+keil

In stm32,inder to use uart rx with DMA, we could easily use:uart Idle interrupt+dma.but how in 52832 while how many byte of a frame to recevie is uncertainty?

in order to test,i designed a master mcu to transmit circulaly,each frame 11byte,period is 1s,baud 1M.

How to config 52832 uarte rx?

my try:set RXD.MAXCNT 255(a big buf). A time hanlder function(detect_a_frame)  which call back each this funtion,read RXD.AMOUNT ,judge wheather recevie amount of buf had changed.if its amount unequal to 0,also stop change,regard a frame recevie function to change rx dma fifo manually.

unfortunately, it don't work.because i found that RXD.AMOUNT will not update until fill up below:(the mosaic is the data had recevied, here maybe had run few second)

How could i make it work in case of 1M baud???I really holp for your help or offer a successful demo.Appreciate!!!