CHAPTER 27 FLASH MEMORY
Page 825 of 920
27.7
Data Flash
27.7.1
Data flash overview
An overview of the data flash memory is provided below.
• The user program can rewrite the data flash memory by using the flash data library. For details, refer to RL78
Family Data Flash Library User’s Manual.
• The data flash memory can also be rewritten to through serial programming using the dedicated flash memory
programmer or an external device.
• The data flash can be erased in 1-block (1 KB) units.
• The data flash can be accessed only in 8-bit units.
• The data flash can be directly read by CPU instructions.
• Instructions can be executed from the code flash memory while rewriting the data flash memory (that is,
background operation (BGO) is supported).
• Because the data flash memory is an area exclusively used for data, it cannot be used to execute instructions.
• Accessing the data flash memory is not possible while rewriting the code flash memory (during self-
programming).
• Manipulating the DFLCTL register is not possible while rewriting the data flash memory.
• Transition to the STOP mode is not possible while rewriting the data flash memory.
Caution 1. The data flash memory is stopped after a reset is canceled. The data flash control register
(DFLCTL) must be set up in order to use the data flash memory.
Caution 2. The high-speed on-chip oscillator should be kept operating during data flash rewrite. If it is
kept stopped, it should be operated (HIOSTOP = 0). The flash self-programming library should
be executed after 30
μ
s have elapsed.
Remark
Refer to flash programming mode, see
Содержание RL78/G1H
Страница 941: ...R01UH0575EJ0120 RL78 G1H...