SH7052 datasheet(734/919 Pages) RENESAS

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20.6.2

User Program Mode

After setting FWE, the user should branch to, and execute, the previously prepared

programming/erase control program.

Use the following procedure (figure 20.12) to execute the programming control program that

writes to flash memory (when transferred to RAM).

Execute user application

program

Execute programming/

erase control program in RAM

(flash memory rewriting)

Transfer programming/erase

control program to RAM

FWE = 1

(user program mode)

Write FWE assessment program

and transfer program

Figure 20.12 User Program Mode Execution Procedure

Note:

When programming and erasing, start the watchdog timer so that measures can be taken to

prevent program runaway, etc. Memory cells may not operate normally if

overprogrammed or overerased due to program runaway.

20.7

Programming/Erasing Flash Memory

A software method, using the CPU, is employed to program and erase flash memory in the on-

board programming modes. There are four flash memory operating modes: program mode, erase

mode, program-verify mode, and erase-verify mode. Transitions to these modes are made by

setting the PSU1, ESU1, P1, E1, PV1, and EV1 bits in FLMCR1.

The flash memory cannot be read while it is being written or erased. Install the program to control

flash memory programming and erasing (programming control program) in the on-chip RAM, in

SH7052 Datasheet(PDF) 734 Page - Renesas Technology Corp