Read Once Command - NXP Semiconductors MC9S08SU16 Reference Manual

Table 11-16. Erase Verify Flash Section command error handling
Register
FSTAT
1. As defined by the memory map for NVM
2. As found in the memory map for NVM

11.3.10.4 Read once command

The read once command provides read access to a reserved 64-byte field (8 phrase)
located in the nonvolatile information register of flash. The read once field can only be
programmed once and can not be erased. It can be used to store the product ID or any
other information that can be written only once. It is programmed using the program once
command described in
command must not be executed from the flash block containing the program once
reserved field.
Table 11-17. Read Once command FCCOB requirements
CCOBIX[2:0]
000
001
010
011
100
101
Upon clearing FSTAT[CCIF] to launch the read once command, a read once phrase is
fetched and stored in the FCCOB indexed register. The FSTAT[CCIF] flag will set after
the read once operation has completed. Valid phrase index values for the read once
command range from 0x0000 to 0x0007. During execution of the read once command,
any attempt to read addresses within flash block will return invalid data.
NXP Semiconductors
Error bit Error condition
Set if CCOBIX[2:0] != 010 at command launch
Set if command not available in current mode (see
Set if an invalid global address [23:0] is supplied (see
ACCERR
Set if a misaligned long words address is supplied (global address[1:0] !=
00)
Set if the requested section crosses flash address boundary
FPVIOL None
Set if any errors have been encountered during the read
MGSTAT1
failed
Set if any errors have been encountered during the read
MGSTAT0
failed
Program Once command. To avoid code runaway, the read once
0x04
Read once phrase index (0x0000 – 0x0007)
MC9S08SU16 Reference Manual, Rev. 5, 4/2017
Chapter 11 Flash Memory Module (FTMRH)
FCCOB parameters
Not required
Read once word 0 value
Read once word 1 value
Read once word 2 value
Read once word 3 value
Table 11-4)
1
Table 11-1)
2
or if blank check
2
or if blank check
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