System09
Stack Pointer Initialisation and NMIs #1
Closed dilbert57 opened this issue about 20 years ago
dilbert57 commented about 20 years ago
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.
dilbert57 was assigned almost 18 years ago
dilbert57 closed this almost 18 years ago
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