h8s-2161b Renesas Electronics Corporation., h8s-2161b Datasheet - Page 678

• Manufacturer Part Number: h8s-2161b
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 23 ROM
23.8.1
When writing data or programs to the flash memory, the program/program-verify flowchart shown
in figure 23.11 should be followed. Performing programming operations according to this
flowchart will enable data or programs to be written to the flash memory without subjecting this
LSI to voltage stress or sacrificing program data reliability.
1. Programming must be done to an empty address. Do not reprogram an address to which
2. Programming should be carried out 128 bytes at a time. A 128-byte data transfer must be
3. Prepare the following data storage areas in RAM: a 128-byte programming data area, a 128-
4. Consecutively transfer 128 bytes of data in byte units from the reprogramming data area or
5. The time during which the P bit is set to 1 is the programming time. Figure 23.11 shows the
6. The watchdog timer (WDT) is set to prevent overprogramming due to program runaway, etc.
7. For a dummy write to a verify address, write 1-byte data H'FF to an address whose lower 2 bits
8. The maximum number of repetitions of the program/program-verify sequence to the same bit
Rev. 3.00 Mar 21, 2006 page 624 of 788
REJ09B0300-0300
programming has already been performed.
performed even if writing fewer than 128 bytes. In this case, H'FF data must be written to the
extra addresses.
byte reprogramming data area, and a 128-byte additional-programming data area. Perform
reprogramming data computation and additional programming data computation according to
figure 23.11.
additional-programming data area to the flash memory. The program address and 128-byte
data are latched in the flash memory. The lower 8 bits of the start address in the flash memory
destination area must be H'00 or H'80.
allowable programming times.
The overflow cycle should be longer than (y + z2 +
are B'00. Verify data can be read in words from the address to which a dummy write was
performed.
is (N).
Program/Program-Verify
+ ) s.