Fujitsu FR81S User Manual
CHAPTER 46: WORKFLASH MEMORY
5. Operation
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : WORKFLASH MEMORY
FUJITSU SEMICONDUCTOR CONFIDENTIAL
39
5.9.4. Flash Access Restrictions When Security is ON
Flash access restrictions when security is ON is shown below.
When security is on, the restrictions shown below are created by the start mode.
Table 5-3
Access Restrictions when Security is ON
Operating mode
Access restriction
User /External bus
In normal mode (the state where there are no access restrictions due to the following flash
security violations), there are no restrictions on access to FLASH memory.
If an instruction fetch is performed to the on-chip bus area, a reset request is issued by the
flash security violation reset source. Accesses to the flash memory are not accepted
thereafter.
The flash memory returns to normal state by reset.
Other than
aforementioned.
(Writer, etc)
Access to flash memory is restricted.
The data from reads is masked and 0xFFFF_FFFF is returned. Write commands and
sector erase commands are ignored.
Chip erase commands are accepted. See "5.9.3 Unlocking Flash Security".
MB91520 Series
MN705-00010-1v0-E
2010