大神,
在FDC2212-Q1版本的规格书中,在page16的计算转换时间的例程中,RCOUNT is 512 FREF cycles(RCOUNT=0x0020),而在page25,如下,RCOUNT的值在0x0000-0x00FF是Reserved,因此,“RCOUNT=0x0020”是非法的。这是否前后矛盾啦?
Kailyn Chen:
是的,你很细心,这样看起来应该最小为4096FREF cycles。
Kailyn Chen:
回复 Kailyn Chen:
看了下Page16的描述,不知是不是只是举例说明,需要再确认一下。
aggil liang:
回复 Kailyn Chen:
Hi Kailyn
确认有结果吗?是否规格书存在问题?
而在非车规版本的FDC2212的page17, 下面这个计算时间也存在疑问,16.75ms是怎么算出来的?
The deterministic conversion time of the FDC allows data polling at a fixed interval. For example, if theprogrammed RCOUNT setting is 512 FREF cycles and SETTLECOUNT is 128 FREF cycles, then one conversiontakes 1.8ms (sensor-activation time) + 3.2ms (conversion time) + 0.75ms (channel-switch delay) = 16.75ms perchannel. If the FDC is configured for dual-channel operation by setting AUTOSCAN_EN = 1 andRR_SEQUENCE = 00, then one full set of conversion results will be available from the data registers every33.5ms