Ew0 Mode; Ew1 Mode - Renesas R8C Series User Manual

R8C/1A Group, R8C/1B Group
18.4.1

EW0 Mode

The MCU enters CPU rewrite mode and software commands can be acknowledged by setting the FMR01 bit in
the FMR0 register to 1 (CPU rewrite mode enabled). In this case, since the FMR11 bit in the FMR1 register is
set to 0, EW0 mode is selected.
Use software commands to control program and erase operations. The FMR0 register or the status register can
be used to determine when program and erase operations complete.
During auto-erasure, set the FMR40 bit to 1 (erase-suspend enabled) and the FMR41 bit to 1 (request erase-
suspend). Wait for td(SR-SUS) and ensure that the FMR46 bit is set to 1 (read enabled) before accessing the
user ROM area. The auto-erase operation can be restarted by setting the FMR41 bit to 0 (erase restarts).
To enter program-suspend during the auto-program operation, set the FMR40 bit to 1 (suspend enabled) and the
FMR42 bit to 1 (request program-suspend). Wait for td(SR-SUS) and ensure that the FMR46 bit is set to 1 (read
enabled) before accessing the user ROM area. The auto-program operation can be restarted by setting the
FMR42 bit to 0 (program restarts).
18.4.2

EW1 Mode

The MCU is switched to EW1 mode by setting the FMR11 bit to 1 (EW1 mode) after setting the FMR01 bit to
1 (CPU rewrite mode enabled).
The FMR0 register can be used to determine when program and erase operations complete. Do not execute
software commands that use the read status register in EW1 mode.
To enable the erase-suspend function during auto-erasure, execute the block erase command after setting the
FMR40 bit to 1 (erase-suspend enabled). The interrupt to enter erase-suspend should be in interrupt enabled
status. After waiting for td(SR-SUS) after the block erase command is executed, the interrupt request is
acknowledged.
When an interrupt request is generated, the FMR41 bit is automatically set to 1 (requests erase-suspend) and the
auto-erase operation suspends. If an auto-erase operation does not complete (FMR00 bit is 0) after an interrupt
process completes, the auto-erase operation restarts by setting the FMR41 bit to 0 (erase restarts)
To enable the program-suspend function during auto-programming, execute the program command after setting
the FMR40 bit to 1 (suspend enabled). The interrupt to enter a program-suspend should be in interrupt enabled
status. After waiting for td(SR-SUS) after the program command is executed, an interrupt request is
acknowledged.
When an interrupt request is generated, the FMR42 bit is automatically set to 1 (request program-suspend) and
the auto-program operation suspends. When the auto-program operation does not complete (FMR00 bit is 0)
after the interrupt process completes, the auto-program operation can be restarted by setting the FMR42 bit to 0
(programming restarts).
Rev.1.30 Dec 08, 2006
REJ09B0252-0130
Page 252 of 315
18. Flash Memory