Datasheet

Section 19 ROM
Rev.6.00 Sep. 27, 2007 Page 888 of 1268
REJ09B0220-0600
19.27.2 RAM Overlap
An example in which flash memory block area EB1 is overlapped is shown below.
H'000000
H'001000
H'002000
H'030000
H'004000
H'005000
H'006000
H'007000
H'008000
H'07FFFF
Flash memory
EB8 to EB15
This area can be accessed
from both the RAM area
and flash memory area
EB0
EB1
EB2
EB3
EB4
EB5
EB6
EB7
H'FFDC00
H'FFEBFF
H'FFFBFF
On-chip RAM
Figure 19.75 Example of RAM Overlap Operation
Example in which Flash Memory Block Area EB1 is Overlapped
1. Set bits RAMS, RAM2, RAM1, and RAM0 in RAMER to 1, 0, 0, 1, to overlap part of RAM
onto the area (EB1) for which real-time programming is required.
2. Real-time programming is performed using the overlapping RAM.
3. After the program data has been confirmed, the RAMS bit is cleared, releasing RAM overlap.
4. The data written in the overlapping RAM is written into the flash memory space (EB1).
Notes: 1. When the RAMS bit is set to 1, program/erase protection is enabled for all blocks
regardless of the value of RAM2, RAM1, and RAM0 (emulation protection). In this
state, setting the P1 or E1 bit in flash memory control register 1 (FLMCR1), or setting