RX610 Group
26. ROM (Flash Memory for Code Storage)
R01UH0032EJ0120 Rev.1.20
Page 848 of 1006
Feb 20, 2013
Note: * Cannot be used in a product whose ROM size is equal to or smaller than 1 Mbyte.
(3) ROM Lock-Bit Read Mode
The ROM lock-bit read mode is for reading the values of the lock bits of the ROM. The FCU enters this mode when a
lock-bit read mode transition command is received in ROM P/E modes. Table 26.9 lists the acceptable commands in this
mode.
In read access to an address within the range for programming and erasure while the FENTRY1* and FENTRY0 bits in
FENTRYR are 1, all bits of the value read out have the value of the lock bit of the erasure block that includes the
accessed address.
Note: * Cannot be used in a product whose ROM size is equal to or smaller than 1 Mbyte.
26.6.2
FCU Commands
FCU commands consist of commands for mode transitions of the FCU and commands for programming and erasure.
Table 26.7 lists the FCU commands for use with the ROM.
Table 26.7 FCU Commands for Use with the ROM
Command
Description
P/E normal mode transition
Changes the mode to normal mode (see section 26.6.3, Connections between FCU
Status read mode transition
Changes the mode to status read mode (see section 26.6.3, Connections between
Lock bit read mode transition
(lock bit read 1)
Changes the mode to lock bit read mode (see section 26.6.3, Connections between
Peripheral clock notification
Sets the frequency of the peripheral clock
Programming
ROM programming (in 256-byte units)
Block erasure
ROM erasure (in block units, with the lock bit being erased simultaneously)
P/E suspension
Suspends programming/erasure
P/E resumption
Resumes programming/erasure
Status register clearing
Clears the ILGLERR, ERSERR and PRGERR bits in FSTATR0 and releases the FCU
from the command locked state
Lock bit read 2/blank checking
Reads the lock bit of a specified erasure block
(the value of the lock bit is reflected in
the FLOCKST bit of FSTATR1)/blank checking of the data-flash memory
Lock bit programming
Programs the lock bit of a specified erasure block
The lock bit read 2 command is also used as the blank-checking command for the data-flash memory. That is, when a
lock bit read 2 command is issued for the data flash, blank checking is executed for the data-flash memory (see section
27, Data Flash (Flash Memory for Data Storage)).
Commands for the FCU are issued by write access to addresses within the range for programming and erasure. Table
26.8 shows the formats of the FCU commands. Write access as listed in table 26.8 and in accord with certain conditions
causes the FCU to execute processing for the corresponding command. For details on the conditions for the acceptance of
the individual FCU commands, see section 26.6.3, Connections between FCU Modes and Commands. For how to use the
FCU commands, see section 26.6.4, FCU Command Usage.