用mcbsp作数据发送,给dxr1赋要传送的数据之前,我想检验xrdy是否为1,也就是是否可以给dxr1赋值了,由于xrdy是spcr2寄存器的第1位,因此我需要先读取spcr2的值,请问该用何种指令? stm #spcr2,spsa0 这里该如何读取spsd0的值? | |
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不能直接使用SPCR2,得先将#1写入SPSA0,选择SPCR2,然后就可以使用LDM 39H,A或将DP=0,使用ORM,BITF,CMPM,等判断。 | |
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pc和F240串口通讯,时通时不通?作何解释? | |
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看看波特率设置对不对,我自己板子上的UART工作得很好。 | |
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McBSP当作普通同步串口用是否要注意什么问题? | |
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设置与原来的串口基本一致,主要注意: 1)帧同步信号,时针信号是输入还是输出? 2)一个帧(FRAME)中是双相(DUAL PHASE) 还是单相(SINGLE PHASE)? 3)一个帧中的字长和每个字的比特数 4)中断产生的方式? 其它设置使用缺省设置就可以了.给你一个参考: 发送设置 SPCR1 = 0x0001 SPCR2 = 0x0030 Transmitter reset, transmit interrupt (XINT to CPU) generated by XSYNCERR; receiver is running with RINT driven by RRDY. FRST & GRST =0 PCR = 0x0A00 FSX determined by FSGM in SRGR, transmit clock driven by external source, receive clock continues to be driven by external source !! SRGR1 = 0x0001 SRGR2 = 0x2000 CPU clock drives the sample rate generator clock (CLKG) after a divide-by-2. A DXR[1,2]-to-XSR[1,2] copy generates the transmit frame-sync signal. XCR1 = 0x0840 XCR2= 0x8421 Dual-phase frame; phase 1 has eight 16-bit words; phase 2 has four 12-bit words, and 1-bit data delay SPCR2 = 0x0031 Transmitter taken out of reset | |
[此贴子已经被作者于2005-12-27 13:58:10编辑过] |