7906 datasheet(385/531 Pages) RENESAS

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FLASH MEMORY VERSION

7906 Group User’s Manual Rev.2.0

19-8

19.1 Overview

19.1.3 Boot mode

When being reset with pin MD1 tied to Vcc level and pin MD0 to Vss level, the flash memory version enters

the boot mode. In the boot mode, the software in the boot ROM area is executed after reset.

In the boot mode, either the boot ROM area or the user ROM area can be selected with the user ROM

area select bit (bit 5 at address 9E16). The boot ROM area is located at addresses E00016 to FFFF16 in the

boot mode.

A reprogramming control firmware used in the flash memory serial I/O mode has been stored in the boot

ROM area on shipment. (Refer to section “19.3 Flash memory serial I/O mode.”) Therefore, when being

reset in the boot mode, the flash memory version enters the flash memory serial I/O mode, allowing the

user ROM area to be reprogrammed with a dedicated serial programmer.

Also the boot ROM area can be reprogrammed in the flash memory parallel I/O mode. If an appropriate

reprogramming control software using the CPU reprogramming mode has been stored in the boot ROM

area, reprogramming suitable for the user’s system is enabled.

Note that if the boot ROM area has been reprogrammed in the flash memory parallel I/O mode, the flash

memory serial I/O mode cannot be used.

7906 Datasheet(PDF) 385 Page - Renesas Technology Corp