M16C Datasheet, PDF (220/262 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Preliminary Specifications REV.B
Mitsubishi microcomputers
Specifications in this manual are tentative and subject to change.
M16C / 6N Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
CPU Rewrite Mode
Page Program Command (4116)
Page program allows for high-speed programming in units of 256 bytes. Page program operation starts
when the command code "4116" is written in the first bus cycle. In the second cycle through the 129th
bus cycle, the write data are sequentially written 16 bits at a time. At this time, the addresses A0 to A7
need to be increased by 2 from "0016" to "FE16". When the system finishes loading the data it starts an
auto write operation (data program and verify operation).
Whether or not the auto write operation is completed can be confirmed by reading the status register or
the flash memory control register. At the same time the auto write operation starts, the read status
register mode is automatically entered, so the content of the status register can be read out. The status
register bit 7 (SR7) is set to 0 at the same time the auto write operation starts and is returned to 1 upon
completion of the auto write operation. In this case, the read status register mode remains active until
the Read Array command (FF16) or Read Lock Bit Status command (7116) is written or the flash
memory is reset using its reset bit.
The RY/BY status flag of the flash memory control register is 0 during the auto write operation and 1
when the auto write operation is completed as is the status register bit 7.
After the auto write operation is completed, the status register can be read out to know the result of the
auto write operation. For details, refer to the section where the status register is detailed.
Figure 23-3 shows an example of a page 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 in the already programmed pages are prohibited.
Start
Write 4116
n=0
Write address n and
data n
n = FE16 ^NO
YES
Read status register
NO
SR7 = 1?
YES
Check full status
Page program
completed
Figure 23-4. Page program flowchart
220
n=n+2