
25. Flash Memory
25.3.3
Software Commands
Read or write commands and data from or to even addresses in the user ROM area in words.
When writing a command code, 8 high-order bits (D15 to D8) are ignored.
Table 25.4
Software Commands
SRD: Data in the status register (D7 to D0)
WA: Write address (The address specified in the first bus cycle is the same even address as the write address
specified in the second bus cycle.)
WD: 16-bit write data
BA: Highest-order even address of a block
x: Given even address in the user ROM area
xx: 8 high-order bits of command code (ignored)
25.3.3.1
Read Array Command
The read array command is used to read the flash memory.
The flash memory enters read array mode when the command code xxFFh is written in the first bus cycle. The
content of the specified address can be read in words when a read address is specified in the next bus cycle. The
flash memory remains in read array mode until the other command is written. Therefore, the contents of
multiple addresses can be read in succession.
25.3.3.2
Read Status Register Command
Register) for details). When the command code xx70h is written in the first bus cycle, the status register can be
read in the second bus cycle. To read the status register, read an even address in the user ROM area.
25.3.3.3
Clear Status Register Command
The clear status register command is used to clear the status register. When the command code xx50h is written
in the first bus cycle, bits FMR07 and FMR06 in the FMR0 register are set to 00b and bits SR5 and SR4 in the
status register are set to 00b.
Software Command
First Bus Cycle
Second Bus Cycle
Mode
Address
Data
(D15 to D0)
Mode
Address
Data
(D15 to D0)
Read array
Write
xxFFh
Read status register
Write
x
xx70h
Read
x
SRD
Clear status register
Write
x
xx50h
Program
Write
WA
xx40h
Write
WA
WD
Block erase
Write
x
xx20h
Write
BA
xxD0h
Lock bit program
Write
BA
xx77h
Write
BA
xxD0h
Read lock bit status
Write
x
xx71h
Write
BA
xxD0h