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问:有一种ADC产品说明在串行接口中推荐使用非连续时钟,为什么? 答:这种技术要求可能是指ADC在转换过程期间要求其时钟信号无效。有的ADC有这种要求,因为连续的时钟信号能够馈送到ADC的模拟部分,反过来会影响转换结果。如果I/O端口有一个帧脉冲,那么连续的时钟信号在转换期间可能变成不连续。这个帧脉冲用作门控信号,只有在数据传递时才允许将串行时钟送到ADC。 问:如何使设备与SPI或MICROWIRE接口标准兼容? 答:SPI(串行外围接口)与MICROWIRE分别是美国摩托罗拉公司和国家半导体公司研制的串行接口标准。大多数同步串行式数据转换器都很容易与这两种接口连接,但是在有些情况下可能需要附加连接逻辑(glue logic)。
Q. There is an ADC product description that recommends the use of non-contiguous clocks in the serial interface. Why? A: This technical requirement may mean that the ADC requires its clock signal to be inactive during the conversion process. Some ADCs have this requirement because the continuous clock signal can be fed to the analog portion of the ADC, which in turn can affect the conversion result. If the I / O port has a frame pulse, successive clock signals may become discontinuous during the conversion. This frame pulse is used as a gate signal, allowing the serial clock to be sent to the ADC only when data is being transferred. Q: How to make the device compatible with SPI or MICROWIRE interface standard? A: SPI (Serial Peripheral Interface) and MICROWIRE are the serial interface standards developed respectively by Motorola and National Semiconductor. Most synchronous serial data converters are easily interfaced with both interfaces, but in some cases additional glue logic may be required.