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A comment on Tomu, a tiny ARM microprocessor which fits in your USB port. Parent comment

Re:Tomu, a tiny ARM microprocessor which fits in your USB port by pkaye on Wednesday August 08, 2018 @10:13PM (#17721244)
Years back I used to work for a company that built 8051 clones. It was possible to prevent the microprocessor from reading the flash memory because the 8051 has a separate program memory and data memory space.
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Re:Tomu, a tiny ARM microprocessor which fits in your USB port by vardump on Thursday August 09, 2018 @03:24AM (#17722225)
I don't understand how that helps to prevent reading anything.

8051 can read data from both CODE and XDATA memory spaces.

See: http://www.keil.com/support/man/docs/is51/is51_movc.htm

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Re:Tomu, a tiny ARM microprocessor which fits in your USB port by pkaye on Thursday August 09, 2018 @01:54PM (#17726631)
Forgot to mention those two instruction will be disabled in flash protected mode.
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