SPI写操作之间出现长暂停

我需要控制一个外部ADC，一个AD5664，从一个PIC32 MZ通过SPI。通信工作正常，但速度很慢。时钟设置为50兆赫。要设置所有四个通道，我需要发送4组24位，总共96位，在50 MHz时应该略小于2个。然而，整个通信需要大约15个美国！在示波器上，我注意到每组24位都需要正确的发送时间，即时钟是正确的，但是每组之间有很长的延迟。也就是说，从我发出WrdEffFuffelHub句柄到SDO线发送第一位的时间大约有3个。在连续写入操作之间也有大约3个美国。此外，AD566R需要在每组24位之前和之后的同步信号，所以我使用SPI驱动程序中的回调来启动和操作，并且我看到同步线下降和第一位出现在SDO线之间的长停顿，并且在最后一个之间有较长的延迟。组中的位和同步线返回。MCU是PIC32 MZ2048 EFG064。我使用的是和声V1.11。对什么是错误的有什么想法？



      以下为原文

    I need to control an external ADC, an AD5664R, from a PIC32MZ through SPI. The communication works properly but it's very slow. The clock is set to 50 MHz. To set all four channels I need to send 4 groups of 24 bits, for a total of 96 bits, which at 50 MHz should take a little less than 2 us. However, the entire communication takes about 15 us! On the oscilloscope I noticed that each group of 24 bits takes the correct amount of time to be sent out, that is the clocking is correct, but there are long delays between each group. Namely, from the time I issue the Write_Buffer_Handle to the time the first bit is sent out on the SDO line there are about 3 us. There are also about 3 us between consecutive write operations. Moreover, the AD5664R requires a SYNC signal before and after each group of 24 bits, so I use callbacks in the SPI Driver for operationStarting and operationEnded, and I see long pauses between the SYNC line going down and the first bit coming out of the SDO line, and a longer delay between the last bit in the group and the SYNC line going back up. The MCU is a PIC32MZ2048EFG064. I'm using HARMony V1.11. Any ideas on what can be wrong?