h8s-2649 Renesas Electronics Corporation., h8s-2649 Datasheet - Page 587

• Manufacturer Part Number: h8s-2649
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

19.8
A software method using the CPU is employed to program and erase flash memory in the on-
board programming modes. Depending on the FLMCR1 setting, the flash memory operates in one
of the following four modes: Program mode, program-verify mode, erase mode, and erase-verify
mode. The programming control program in boot mode and the user program/erase control
program in user program mode use these operating modes in combination to perform
programming/erasing. Flash memory programming and erasing should be performed in
accordance with the descriptions in section 19.8.1, Program/Program-Verify and section 19.8.2,
Erase/Erase-Verify, respectively.
19.8.1
When writing data or programs to the flash memory, the program/program-verify flowchart shown
in figure 19.9 should be followed. Performing programming operations according to this flowchart
will enable data or programs to be written to the flash memory without subjecting the chip 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 19.10 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
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 19.10.
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.
Set a value greater than (tspsu + tsp200 + tcp + tcpsu) µs as the WDT overflow period.
are B'00. Verify data can be read in words from the address to which a dummy write was
performed.
Flash Memory Programming/Erasing
Program/Program-Verify
Rev. 2.00 Dec. 05, 2005 Page 549 of 724
REJ09B0200-0200
Section 19 ROM