System09

Non Maskable Interrupts should be masked until the S stack pointer is initialised with an LDS (Load S) , LEAS (Load Effective Address), TFR <reg>,S (Transfer to S) and EXG <reg>,S (Exchange Register with S) and EXG S,<reg> (Exchange S with regsiter). This is to prevent NMI's from interrupting the CPU before the S stack pointer is initialised.

Its probably most easily done in the register control code.

J.K.

Problem Fixed in 16th July 2006 revision

J.K.