Am335x使用MCASP0的TDM模式连接两个或四个支持TDM的 codec,硬件接口电路是怎么样的?有没有相关文档说明?
Shine:
一个codec接一路AXRn。如果codec是多路的话,可以有两种接法,看一下user guide.
22.3.3.1.1 TDM Formathttp://www.ti.com/lit/ug/spruh73p/spruh73p.pdf
For example, a particular six channel DAC may be designed to transfer over a single serial data pin AXRnas shown in Figure 22-8. In this case the serial clock must run fast enough to transfer a total of 6 channelswithin each frame period. Alternatively, a similar six channel DAC may be designed to use three serialdata pins AXR[0,1,2], transferring two channels of data on each pin during each sample period. In thelatter case, if the sample period remains the same, the serial clock can run three times slower than theformer case. The McASP is flexible enough to support either type of DAC.
dznihao:
回复 Shine:
如图AM335X的MCASP1 与CODEC 连接,如果只连接下面这几个信号:
MCASP1_FSX 接CODEC的BCLKMCASP1_ACLKX 接CODEC的WCLKMCASP1_AXR0 接CODEC的DINMCASP1_AXR1接CODEC的DOUT
MCASP1_FSX和MCASP1_ACLKX都是Transmit,所以这个硬件连接只能完成单向的从AM335X 到CODEC通信? MCASP1_AXR1接CODEC的DOUT是没有意义的,应为AM335X 没有接receive的相关CLOCK,想问下是不是可以这样理解?
如果要实现AM335X 既为master,又可以为slave , 这种CODEC 的BCLK和WCLK是不是要同时接到CASP1_FSX ,CASP1_FSR ,MCASP1_ACLKX, MCASP1_ACLKR来实现transmit和receive的相关CLOCK信号。