HD64F3644PV Datasheet, PDF (148/551 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 6 ROM
User Program Mode Execution Procedure^*1: The procedure for user program execution in
RAM is shown below.
1
Reset-start (TEST = V_SS)
2
Branch to flash memory on-board
reprogramming program
Transfer flash memory
3
reprogramming routine to RAM
Branch to flash memory
4 _{reprogramming routine in RAM area}
5
FV_PP = 12 V
(user program mode)
Execute flash memory
6 _{reprogramming routine in RAM area}
(flash memory reprogramming)
7
Release FV_PP
(exit user program mode)
Procedure:
An on-board reprogramming program must be written into
flash memory by the user beforehand.
1. Set the TEST pin to V_SS and execute a reset-start.
2. Branch to the on-board reprogramming program written to
flash memory.
3. Transfer the flash memory reprogramming routine to the
RAM area.
4. Branch to the flash memory reprogramming routine
transferred to the RAM area.
5. Apply 12 V to the FV_PP pin. (Transition to user program
mode)
6. Execute the flash memory reprogramming routine in the
RAM area, an perform on-board reprogramming of the
flash memory.
7. Switch the FV_PP pin from 12 V to V_CC, and exit user
program mode.
8. After on-board reprogramming of the flash memory ends,
branch to the flash memory application program.
8
Branch to flash memory application
program^*2
Notes: 1. Do not apply 12 V to the FV_PP pin during normal operation. To prevent inadvertent programming or
erasing due to program runaway, etc., apply 12 V to the FV_PP pin only when the flash memory is
being programmed or erased . Memory cells may not operate normally if overprogrammed or
overerased due to program runaway, etc. Also, while 12 V is applied to the FV_PP pin, the watchdog
timer should be activated to prevent overprogramming or overerasing due to program runaway, etc.
For further information on FV_PP application, release, and cut-off, see note 5 in section 6.9, Flash
Memory Programming and Erasing Precautions.
2. When the application of 12 V to the FV_PP pin is released after programming is completed, the flash
memory read setup time (t_FRS) must elapse before executing a program in flash memory. This
specifies the setup time from the point at which the FV_PP voltage reaches the V_CC + 2 V level after
12 V application is released until the flash memory is read.
Figure 6.12 Example of User Program Mode Operation
Rev. 6.00 Sep 12, 2006 page 126 of 526
REJ09B0326-0600