ZHCABI9 April 2022 TDA4VM
还利用在上述步骤 3.3 中编译的 spidev_test 来演示从模式功能。
使用 spidev_test 实用程序启动 MCPSI4 从器件和 MCU_MCSPI2 之间的通信。
上述测试的日志:
root@j7200-evm:~# echo spidev > /sys/class/spi_slave/spi2/slave
root@j7200-evm:~# ./spidev_test -v -D /dev/spidev2.0 -p slave-hello-to-master &
[1] 1186
root@j7200-evm:~# ./spidev_test -v -D /dev/spidev0.0 -p master-hello-to-slave
spi mode: 0x0
bits per word: 8
max speed: 500000 Hz (500 kHz)
spi mode: 0x0
bits per word: 8
max speed: 500000 Hz (500 kHz)
TX | 6D 61 73 74 65 72 2D 68 65 6C 6C 6F 2D 74 6F 2D 73 6C 61 76 65 __ __ __ __ __ __ __ __ __ __ __ |master-hello-to-slave|
RX | 73 6C 61 76 65 2D 68 65 6C 6C 6F 2D 74 6F 2D 6D 61 73 74 65 72 __ __ __ __ __ __ __ __ __ __ __ |slave-hello-to-master|
TX | 73 6C 61 76 65 2D 68 65 6C 6C 6F 2D 74 6F 2D 6D 61 73 74 65 72 __ __ __ __ __ __ __ __ __ __ __ |slave-hello-to-master|
RX | 6D 61 73 74 65 72 2D 68 65 6C 6C 6F 2D 74 6F 2D 73 6C 61 76 65 __ __ __ __ __ __ __ __ __ __ __ |master-hello-to-slave|
可以看到主器件 MCU_MCSPI2 发送了 TX 消息 master-hello-to-slave,并从 MCPSI4 从器件接收了 RX 消息 slave-hello-to-master,反之亦然。