R8CSLASH2G datasheet(277/344 Pages) RENESAS

277 / 344 page

R8C/2G Group

20. Flash Memory

Rev.1.00

Apr 04, 2008

Page 257 of 318

REJ09B0387-0100

• Read Array Command

The read array command reads the flash memory.

When FFh is written to an address in the user ROM area, the MCU enters read array mode. In this mode,

the contents of the specified address can be read.

Read array mode continues until other commands are written. The MCU enters this mode after a reset is

deasserted.

• Read Status Register Command

The read status register command is used to read the status register. Figure 20.9 shows Status Register.

The status register indicates the operating status of the flash memory and whether an erase or program

operation has completed normally or in error (refer to Table 20.4 Errors and FMR0 Register Status).

When 70h is written to an address in the user ROM area, the MCU enters read status register mode. When

the address in the user ROM area is read subsequently, the status register can be read.

The MCU remains in read status register mode until the next read array command is written.

The status of the status register can be determined by reading bits FMR00, FMR06, and FMR07 in the

FMR0 register.

Figure 20.9

Status Register

• Clear Status Register Command

The clear status register command sets the status register to 0.

When 50h is written to an address in the user ROM area, bits FMR07 and FMR06 in the FMR0 register and

bits SR5 and SR4 in the status register are set to 00b.

SR7 SR6 SR5 SR4 SR3 SR2 SR1 SR0

Status register

FMR0 register

FMR06 bit

FMR07 bit

FMR00 bit

D0 to D7: These indicate the read data buses when the read status command is executed.

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