Difference between revisions of "84PCE:Ports:0028"

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(Created page with "0028 - Unknown == Synopsis == '''Port Number:''' 0028 '''Function:''' Unknown == Details == This port's function is unknown. === Bit [0...")
 
(Synopsis)
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'''Port Number:''' 0028
 
'''Port Number:''' 0028
  
'''Function:''' Unknown
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'''Function:''' Flash locked status
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Flash is unlocked iff bits 2 and 3 of this port are both set.
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bit 2: can be modified freely (under the usual protected port constraints)
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bit 3: can be cleared by writing a 0 or any time unprivileged code is executed, fetching the flash unlock sequence (F31800F3F3ED7EED56ED3928ED3828CB57) ending in privileged flash is the only way to set it
  
 
== Details ==
 
== Details ==

Revision as of 21:42, 7 August 2017

Synopsis

Port Number: 0028

Function: Flash locked status

Flash is unlocked iff bits 2 and 3 of this port are both set.

bit 2: can be modified freely (under the usual protected port constraints)

bit 3: can be cleared by writing a 0 or any time unprivileged code is executed, fetching the flash unlock sequence (F31800F3F3ED7EED56ED3928ED3828CB57) ending in privileged flash is the only way to set it

Details

This port's function is unknown.

Bit [0]

Latches value written, no apparent effect.

Bit [1]

Always 0, writes do not latch.

Bit [2]

Latches value written, no apparent effect.

Bits [7:3]

Writes do not latch, no apparent effect.