M16C26 Datasheet, PDF (203/239 Pages) Renesas Technology Corp – 16-BIT CMOS SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/20 SERIES

Udenvdeelropment
Preliminary Specifications Rev. 0.9
Specifications in this manual are tentative and subject to change.
CPU Rewrite Mode (Flash Memory Version)
M16C/26 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Program Command (4016)
Program operation starts when the command code “4016” is written in the first bus cycle. Then, if the
address and data to program are written in the 2nd bus cycle, program operation (data programming
and verification) will start. Make an address in the first bus cycle same as an address to program by
the second bus cycle.
Whether the write operation is completed can be confirmed by reading the status register or the RY/
BY status flag. When the program starts, the read status register mode is accessed automatically and
the content of the status register is read into the data bus (D0 - D7). The status register bit 7 (SR7) is
set to 0 at the same time the write operation starts and is returned to 1 upon completion of the write
operation. In this case, the read status register mode remains active until the Read Array command
(FF16) is written.
The RY/BY status flag is 0 during write operation and 1 when the write operation is completed as is
the status register bit 7.
At program end, program results can be checked by reading the status register.
Figure 1.20.3 shows an example of a program flowchart.
Each block of the flash memory can be write protected by using a lock bit. For details, refer to the
section where the data protect function is detailed.
Additional writes to the already programmed pages are prohibited.
Do a command to use in right after of program command as follows
Make an address in the first bus cycle same as an address to program by the second bus cycle of
program command.
Start
Write 4016
Write data to target
address
Status register
read
(Set an address to even address in the
user ROM area when write 4016 )
(Set an address to even address in the user
ROM area when reading the status register)
SR7=1?
NO
or
RY/BY=1?
YES
NO
SR4=0?
YES
Program
completed
Program
error
Figure 1.20.3. Program flowchart
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