Register Description; Flash Memory Control Register 0 (Fmr0); Fmr 00 Bit; Fmr01 Bit - Renesas M16C/29 Series Hardware Manual

M16C/29 Group

21.5 Register Description

Figure 21.5.1 shows the flash memory control register 0 and flash memory control register 1. Figure 21.5.2
shows the flash memory control register 4.

21.5.1 Flash memory control register 0 (FMR0):

•FMR 00 Bit

This bit indicates the operation status of the flash memory. The bit is "0" during programming, erasing,
or erase-suspend mode; otherwise, the bit is "1".

•FMR01 Bit

The microcomputer can be placed in CPU erase-write mode when this bit is "1". It allows flash instruc-
tions to be executed. To set this bit to "1", it is necessary to set to "1" after first setting to "0". Set this bit
to "0" by only writing "0".

•FMR02 Bit

The combined setting of the FMR02 bit and the FMR16 bit enable to program and erase in the user
ROM area. See Table 21.5.2.1 for setting details. Set this bit to "1", it is necessary to set to "1" after
first setting to "0". To set this bit to "0" by only writing "0". This bit is enabled only when the FMR01 bit
is "1" (CPU rewrite mode enable).

•FMSTP Bit

This bit resets the flash memory control circuits and minimizes power consumption in the flash
memory. Access to the flash memory is disabled when the FMSTP bit is set to "1". Set the FMSTP bit
by a program in a space other than the flash memory.
Set the FMSTP bit to "1" if one of the following occurs:
•A flash memory access error occurs during erasing or programming located in an area outside the
flash memory.
•Low-power consumption mode or on-chip oscillator low-power consumption mode is entered. Figure
21.5.1.3 shows a flow chart illustrating how to start and stop the flash memory before and after enter-
ing low power mode. Follow the procedure on this flow chart.

•FMR06 Bit

This is a read-only bit indicating an auto-program operation status. This bit is set to "1" when a pro-
gram error occurs; otherwise, it is set to "0". For details, refer to the description of the full status check.

•FMR07 Bit

This is a read-only bit indicating an auto-erase operation status. The bit is set to "1" when an erase
error occurs; otherwise, it is set to "0". For details, refer to the description of the full status check.
Figure 21.5.1.1 shows a EW0 mode set/reset flowchart, figure 21.5.1.2 shows a EW1 mode set/reset
flowchart.
Rev.1.00 Nov 01,2004
REJ09B0101-0100Z
page 374 of 402
21. Flash Memory Version