解决方案ID: rd09182000_9813
最后修改: 2006 年2 月13 日
产品类别: N/A
产品领域: N/A
产品子领域: N/A

标题

Why is CONF_DONE never driving low on power-up, and/or why is the device drawing excessive power in an APEX 20KE device?

说明

One possible cause of this problem is if you have incorrectly set your MSEL pins as follows:

MSEL0: 1 (VCC)
MSEL1: 0 (GND)

This will put your APEX device into test mode, in which the device will never drive CONF_DONE low. When the device is in this mode and it detects that the CONF_DONE pin is high (due to the external pull-up resistor), the device enters user mode with a random configuration pattern. Since the pins are now driving out randomly, it is possible that contention occurs and the device will draw excessive power.

In addition, the device can enter test/scan mode when the MSEL pins are left floating.

If you are still experiencing problems after verifying that your MSEL pins are properly connected on the board, please contact Altera Applications for further assistance.

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Altera并不保证此解决方案能够达到客户的预期目的，并不承担所有的解决方案的使用和信赖的责任。