SNLA417 January 2023 DP83TC812R-Q1 , DP83TC812S-Q1
The DP83TC812-Q1 supports an MDC up to 25 MHz. If a MAC interface supports an MDC of 25 MHz, this time can be further optimized as the following equation shows.
Δtms_cfg = 90 instructions × 32 bits × (1/25 MHz) = 0.23ms. This is 3.799ms less than the actual time measured.