RX610 Group
26. ROM (Flash Memory for Code Storage)
R01UH0032EJ0120 Rev.1.20
Page 847 of 1006
Feb 20, 2013
26.6.1.1
ROM Read Modes
The ROM read modes are for high-speed reading of the ROM. Access to an address for reading can be accomplished in
one cycle of ICLK.
ROM/data-flash read mode and data-flash P/E mode are the two kinds of ROM reading mode.
(1) ROM/Data Flash Read Mode
This mode is for reading the ROM and data-flash memory. The FCU does not accept commands.
The FCU enters this mode when the FENTRY1* and FENTRY0 bits in FENTRYR are set to 0, and the FENTRYD bit in
FENTRYR is set to 0.
(2) Data Flash P/E Modes
These modes are for programming and erasure of the data-flash memory. High-speed reading of the ROM is also possible.
Although the FCU accepts FCU commands related to the data-flash memory in this mode, it does not accept FCU
commands related to the ROM. The FCU enters these modes when the FENTRY1* and FENTRY0 bits in FENTRYR are
set to 0, or the FENTRYD bit in FENTRYR is set to 1.
For details on the data flash P/E modes, see section 27.6.1, FCU Modes
26.6.1.2
ROM P/E Modes
The ROM P/E modes are for programming and erasure of the ROM. High-speed reading of the ROM is not possible in
these modes. Read access to an address within the range for reading causes a ROM-access violation, and the FCU enters
the command-locked state (see section 26.8.2, Error Protection).
ROM P/E normal mode, ROM status read mode, and ROM lock-bit read mode are the three ROM P/E modes.
(1) ROM P/E Normal Mode
The transition to ROM P/E normal mode is the first transition in the process of programming or erasing the ROM. The
FCU enters this mode when the FENTRYD bit in FENTRYR is set to 0, and either the FENTRY1* or FENTRY0 bit in
FENTRYR is set to 1 in ROM read mode, or when the normal mode transition command is received in ROM P/E modes.
Table 26.9 lists the acceptable commands in this mode.
Read access to an address within the range for programming and erasure while the FENTRY1* and FENTRY0 bits in
FENTRYR are set to 1 causes a ROM-access violation, and the FCU enters the command-locked state (see section 26.8.2,
Error Protection).
(2) ROM Status Read Mode
The ROM status read mode is for reading information on the state of the ROM. The FCU enters this mode when a
command other than the normal mode transition and lock bit read mode transition command is received in ROM P/E
modes.
ROM status read mode encompasses the states where the FRDY bit in FSTATR0 is 0 and the command-locked state after
an error has occurred. Table 26.9 lists the acceptable commands in this mode.
Read access to an address within the range for programming and erasure while the FENTRY1* and FENTRY0 bits in
FENTRYR are 1 will actually read out the value of FSTATR0.
Summary of Contents for RX600 Series
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