R8CSLASH20 datasheet(393/501 Pages) RENESAS

393 / 501 page

R8C/20 Group, R8C/21 Group

19. Flash Memory

Rev.2.00 Aug 27, 2008

Page 377 of 458

REJ09B0250-0200

19.2

Memory Map

The flash memory contains a user ROM area and a boot ROM area (reserved area).

Figure 19.1 shows the Flash Memory Block Diagram for R8C/20 Group. Figure 19.2 shows the Flash Memory

Block Diagram for R8C/21 Group.

The user ROM area of R8C/21 Group contains an area which stores a MCU operating program (program ROM)

and the 1-Kbyte block A and B (data flash).

The user ROM area is divided into several blocks. The user ROM area can be rewritten in CPU rewrite and

standard serial I/O and parallel I/O modes.

When rewriting the block 0 and block 1 in CPU rewrite mode, set the FMR02 bit in the FMR0 register to 1 (rewrite

enables), and when setting the FMR15 bit in the FMR1 register to 0 (rewrite enables), block 0 is rewritable. When

setting the FMR16 bit to 0 (rewrite enables), block 1 is rewritable.

When rewriting the block 2 and block 3 in CPU rewrite mode, set the FMR02 bit in the FMR0 register to 1 (rewrite

enables).

The rewrite control program for standard serial I/O mode is stored in boot ROM area before shipment. The boot

ROM area and the user ROM area share the same address, but have an another memory.

R8C/20 Datasheet(PDF) 393 Page - Renesas Technology Corp