RX610 Group
26. ROM (Flash Memory for Code Storage)
R01UH0032EJ0120 Rev.1.20
Page 862 of 1006
Feb 20, 2013
(7) Writing to/Erasing Lock Bit
Each erasure block in the user mat includes a lock bit. To write to a lock bit, use the lock bit programming command. In
the first cycle of the lock bit programming command, 77h is programmed to the ROM programming/erasure address in
byte access. When D0h is programmed to an arbitrary address in an erasure block whose lock bit is to be programmed in
the second cycle in byte access, the FCU start the programming processing of the lock bit. Whether programming is
completed can be checked with the FRDY bit in FSTATR0.
Write 77h to ROM programming/
erasure address in byte access
Write D0h to arbitrary address in
erasure block in byte access
FRDY bit check
Timeout
(tP256
×
1.1)
*
FCU initialization
FRESETR.FRESET = 1
writing
ILGLERR bit and PRGERR bit
check
Wait
(tRESW2)
*
FRESETR.FRESET = 0
writing
Note:
*
tP256: Programming time for 256-byte data (see section 29, Electrical Characteristics)
tRESW2: Reset pulse width during programming/erasure (see section 29, Electrical Characteristics)
No
Yes
"0"
"1"
Use the ROM programming/erasure address
(Do not use a read address)
Start
End
Figure 26.16 Program Setting of the Lock Bit
To erase a lock bit, use the block erase command.
When the FPROTCN bit in FPROTR is 0, erasure blocks whose lock bit is set to 0 cannot be erased. When erasing a lock
bit, issue a block erase command with the FPROTCN bit set to 1. Using the block erase command erases all data in the
erasure block. It is impossible to erase only a lock bit.
Summary of Contents for RX600 Series
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