Preliminary User’s Manual U17260EJ3V1UD
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CHAPTER 26 FLASH MEMORY
The 78K0/KE2 incorporates the flash memory to which a program can be written, erased, and overwritten while
mounted on the board.
26.1 Internal Memory Size Switching Register
The internal memory capacity can be selected using the internal memory size switching register (IMS).
IMS is set by an 8-bit memory manipulation instruction.
Reset signal generation sets IMS to CFH.
Caution Be sure to set each product to the values shown in Table 26-1 after a reset release.
Figure 26-1. Format of Internal Memory Size Switching Register (IMS)
Address: FFF0H After reset: CFH R/W
Symbol 7 6 5 4 3 2 1 0
IMS
RAM2 RAM1 RAM0
0
ROM3 ROM2 ROM1 ROM0
RAM2 RAM1 RAM0
Internal
high-speed RAM capacity selection
0 0 0
768
bytes
1 1 0
1024
bytes
Other than above
Setting prohibited
ROM3 ROM2 ROM1 ROM0
Internal
ROM
capacity
selection
0 1 0 0
16
KB
0 1 1 0
24
KB
1 0 0 0
32
KB
1 1 0 0
48
KB
1 1 1 1
60
KB
Other than above
Setting prohibited
Caution To set the memory size, set IMS and then IXS. Set the memory size so that the internal ROM and
internal expansion RAM areas do not overlap.