Flash Memory Registers
5-18 Flash Memory Controller
FCTL1, Flash Memory Control Register
15 14 13 12 11 10 9 8
FRKEY, Read as 096h
FWKEY, Must be written as 0A5h
76543210
BLKWRT WRT Reserved Reserved Reserved MERAS ERASE Reserved
rw0 rw0 r0 r0 r0 rw0 rw0 r0
FRKEY/
FWKEY Bits
15-8 FCTLx password. Always read as 096h. Must be written as 0A5h or a PUC
will be generated.
BLKWRT Bit 7 Block write mode. WRT must also be set for block write mode. BLKWRT is
automatically reset when EMEX is set.
0 Block-write mode is off
1 Block-write mode is on
WRT Bit 6 Write. This bit is used to select any write mode. WRT is automatically reset
when EMEX is set.
0 Write mode is off
1 Write mode is on
Reserved Bits
5-3 Reserved. Always read as 0.
MERAS
ERASE Bit 2
Bit 1 Mass erase and erase. These bits are used together to select the erase mode.
MERAS and ERASE are automatically reset when EMEX is set.
MERAS ERASE Erase Cycle
0 0 No erase
0 1 Erase individual segment only
1 0 Erase all main memory segments
1 1 Erase all main and information memory segments
Reserved Bit 0 Reserved. Always read as 0.