Expansion Bus Control Register

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Number $81
Readable Yes
Writable Yes
Short Description Expansion bus controls
Bit Description
7 1 if ROMCS is being asserted on the expansion bus (Read only, write 0)
4 1 to propagate the max CPU clock at all times including when the expansion bus is off
1-0 max CPU speed when the expansion bus is on (currently fixed at 00 = 3.5MHz)

Set to 0 upon hard reset.

(new register since core 3.0.5)

(note: Next registers with number higher than $7F are inaccessible from Copper code)