Difference between revisions of "84PCE:Ports:0028"
From WikiTI
(Created page with "0028 - Unknown == Synopsis == '''Port Number:''' 0028 '''Function:''' Unknown == Details == This port's function is unknown. === Bit [0...") |
(→Synopsis) |
||
| Line 3: | Line 3: | ||
'''Port Number:''' 0028 | '''Port Number:''' 0028 | ||
| − | '''Function:''' | + | '''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 == | == Details == | ||
Revision as of 20:42, 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.
