R8C/20 Group, R8C/21 Group 19. Flash Memory
Rev.2.00 Aug 27, 2008 Page 397 of 458
REJ09B0250-0200
19.4.4 Status Registers
The status register indicates the operating status of the flash memory and whether an erasing or programming
operation completes normally or in error. Status of the status register can be read by the FMR00, FMR06, and
FMR07 bits in the FMR0 register.
Table 19.5 lists the Status Register Bits.
In EW0 mode, the status register can be read in the following cases:
• When a given address in the user ROM area is read after writing the read status register command
• When a given address in the user ROM area is read after executing the program or block erase command
but before executing the read array command.
19.4.4.1 Sequencer Status (Bits SR7 and FMR00)
The sequencer status indicates operating status of the flash memory. SR7 = 0 (busy) during auto programming
and auto erasing, and is set to 1 (ready) at the same time the operation completes.
19.4.4.2 Erase Status (Bits SR5 and FMR07)
Refer to 19.4.5 Full Status Check.
19.4.4.3 Program Status (Bits SR4 and FMR06)
Refer to 19.4.5 Full Status Check.
• D0 to D7: Indicates the data bus which is read when the read status register command is executed.
• The FMR07 (SR5) to FMR06 bits (SR4) are set to 0 by executing the clear status register command.
• When the FMR07 bit (SR5) or FMR06 bit (SR4) is set to 1, the program and block erase command
cannot be accepted.
Table 19.5 Status Register Bits
Status
Register
Bit
FMR0
Register
Bit
Status Name
Description Value
after
Reset
01
SR0 (D0) − Reserved −−−
SR1 (D1) − Reserved −−−
SR2 (D2) − Reserved −−−
SR3 (D3) − Reserved −−−
SR4 (D4) FMR06 Program status Completed
normally
Error 0
SR5 (D5) FMR07 Erase status Completed
normally
Error 0
SR6 (D6) − Reserved −−−
SR7 (D7) FMR00 Sequencer
status
Busy Ready 1
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