rsv13脚接20欧姆下拉电阻,应该一直为低电平,为什么一直为高电平,是不是dsp坏掉了,静电损伤了???
Yu Liu:
您好!
请问系统是使用RGMII模式吗?如果使用EMAC的RGMII模式文档上没有看出一定是低电平。
When the RGMII mode of the EMAC is not used, the DVDD15, DVDD15MON, VREFHSTL, RSV13, and RSV14
pins can be connected directly to ground (VSS) to save power. However, this will prevent boundary-scan
from functioning on the RGMII pins of the EMAC. To preserve boundary-scan functionality on the RGMII
pins, DVDD15, VREFHSTL, RSV14, and RSV13 should be connected as follows:
• DVDD15 and DVDD15MON – connect these pins to the 1.8-V I/O supply (DVDD18).
• VREFHSTL – connect to a voltage of DVDD18/2. The DVDD18/2 voltage can be generated directly from the
DVDD18 supply using two 1-kΩ resistors to form a resistor divider circuit.
• RSV13 – connect this pin to ground (VSS) via a 200-Ω resistor.
• RSV14 – connect this pin to the 1.8-V I/O supply (DVDD18) via a 200-Ω resistor.
heng liu:
回复 Yu Liu:
你好,刘工,目前板卡上没有用到emac,在其他板卡上rsv13脚都是低电平。
heng liu:
回复 heng liu:
还有会不会虚焊也会造成这种现象吗?
Yu Liu:
回复 heng liu:
虚焊是一种可能性。如果别的板子都是低电平就要考虑硬件问题的可能性了。