How does the Detect JTAG Chain feature (JTAG menu) detect the devices in a JTAG chain?

Description

The MAX PLUS® II software uses the following sequence to detect the devices along a JTAG chain:

1. Measures the instruction register length by shifting a very long string of 1s into the instruction register, then counting a long string of "0"s to replace the "1"s.
2. Verifies the chain by placing each device into BYPASS mode.

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