M37517F8HP Datasheet, PDF (59/98 Pages) Renesas Technology Corp – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER

7517 Group
(1) CPU Rewrite Mode
In CPU rewrite mode, the internal flash memory can be operated
on (read, program, or erase) under control of the Central Process-
ing Unit (CPU).
In CPU rewrite mode, only the User ROM area shown in Figure 64
can be rewritten; the Boot ROM area cannot be rewritten. Make
sure the program and block erase commands are issued for only
the User ROM area and each block area.
The control program for CPU rewrite mode can be stored in either
User ROM or Boot ROM area. In the CPU rewrite mode, because
the flash memory cannot be read from the CPU, the rewrite con-
trol program must be transferred to internal RAM area to be
executed before it can be executed.
Microcomputer Mode and Boot Mode
The control program for CPU rewrite mode must be written into
the User ROM or Boot ROM area in parallel I/O mode beforehand.
(If the control program is written into the Boot ROM area, the stan-
dard serial I/O mode becomes unusable.)
See Figure 64 for details about the Boot ROM area.
Normal microcomputer mode is entered when the microcomputer
is reset with pulling CNVSS pin low. In this case, the CPU starts
operating using the control program in the User ROM area.
When the microcomputer is reset by pulling the P41/INT0 pin high,
the CNVss pin high, the CPU starts operating using the control
program in the Boot ROM area (program start address is FFFC16,
FFFD16 fixation). This mode is called the “Boot” mode.
The User ROM area can be rewritten also by the control program
in the Boot ROM area.
Block Address
Block addresses refer to the maximum address of each block.
These addresses are used in the block erase command. In case
of the M37517F8, it has only one block.
Rev.1.01 Aug 02, 2004 page 59 of 96