I configure both ATD0 and ATD1 in the same way from code ported from a system working with the MC9S12DP256. All the register settings were modified in the port according to guidance in the S12 / S12XE compatibility guide (AN3469) and the S12XE reference manual (MC9S12XEP100RMV1). Signals connected to ATD0 inputs all result in expected A/D conversion values. Nothing connected to ATD1 inputs comes close to correct. In fact, all inputs yield a very similar result, a little less that the midrange of 10-bit, regardless of the voltage level of the input signal (5V A/D reference, inputs of 4.1V, 2.5V, ground, and floating open).