SNLS579A April 2018 – November 2018 DP83TC811S-Q1
Test mode 1 evaluates transmitter droop. In test mode 1, the DP83TC811S-Q1 transmits ‘+1’ symbols for a minimum of 600 ns followed by ‘–1’ symbols for a minimum of 600 ns. This pattern is repeated continuously until the test mode is disabled.
Test mode 1 is enabled by setting bits[15:13] = 0b001 in the TEST_CTRL Register 0x0836 – MMD1 100BASE-T1 PMA Test Control Register.
Additionally, transmit symbol width can be controlled using bits[9:4] in the TEST_MODE_CTRL Register 0x0497 – Test Mode Control Register.