Figure 18.8 Example Of Ram Overlap Operation - Renesas H8S Series Hardware Manual

Section 18 ROM
An example in which flash memory block area EB0 is overlapped is shown in figure 18.8.
1. The RAM area to be overlapped is fixed at a 1-kbyte area in the range H'FFE000 to H'FFE3FF.
2. The flash memory area to overlap is selected by RAMER from a 1-kbyte area of the EB0 to
EB3 blocks.
3. The overlapped RAM area can be accessed from both the flash memory addresses and RAM
addresses.
4. When the RAMS bit in RAMER is set to 1, program/erase protection is enabled for all flash
memory blocks (emulation protection). In this state, setting the P1 or E1 bit in FLMCR1 to 1
does not cause a transition to program mode or erase mode.
5. A RAM area cannot be erased by execution of software in accordance with the erase
algorithm.
6. Block area EB0 contains the vector table. When performing RAM emulation, the vector table
is needed in the overlap RAM.
H'000000
H'0003FF
H'000400
H'0007FF
H'000800
H'000BFF
H'000C00
H'000FFF
H'FFE000
H'FFE3FF
Rev. 6.00 Mar 15, 2006 page 472 of 570
REJ09B0211-0600
Flash memory
(EB0)
(EB1)
(EB2)
(EB3)
On-chip RAM
(1 kbyte)
Normal memory map

Figure 18.8 Example of RAM Overlap Operation

Flash memory
(EB0)
On-chip RAM
(Shadow of
H'FFE000 to
H'FFE3FF)
Flash memory
(EB2)
(EB3)
On-chip RAM
(1 kbyte)
RAM overlap memory map