LM3S9B81 Datasheet, PDF (210/1155 Pages) Texas Instruments – Stellaris® LM3S9B81 Microcontroller

Internal Memory
Register 3: Flash Memory Control (FMC), offset 0x008
When this register is written, the Flash memory controller initiates the appropriate access cycle for
the location specified by the Flash Memory Address (FMA) register (see page 208). If the access
is a write access, the data contained in the Flash Memory Data (FMD) register (see page 209) is
written to the specified address.
This register must be the final register written and initiates the memory operation. The four control
bits in the lower byte of this register are used to initiate memory operations.
Care must be taken not to set multiple control bits as the results of such an operation are
unpredictable.
Flash Memory Control (FMC)
Base 0x400F.D000
Offset 0x008
Type R/W, reset 0x0000.0000
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
WRKEY
Type WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
WO
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
reserved
COMT MERASE ERASE WRITE
Type RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
R/W
R/W
R/W
R/W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bit/Field
31:16
15:4
3
Name
WRKEY
reserved
COMT
Type
WO
RO
R/W
Reset
0x0000
0x000
0
Description
Flash Memory Write Key
This field contains a write key, which is used to minimize the incidence
of accidental Flash memory writes. The value 0xA442 must be written
into this field for a Flash memory write to occur. Writes to the FMC
register without this WRKEY value are ignored. A read of this field returns
the value 0.
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
Commit Register Value
This bit is used to commit writes to Flash-memory-resident registers
and to monitor the progress of that process.
Value Description
1 Set this bit to commit (write) the register value to a
Flash-memory-resident register.
When read, a 1 indicates that the previous commit access is
not complete.
0 A write of 0 has no effect on the state of this bit.
When read, a 0 indicates that the previous commit access is
complete.
A commit can take up to 50 μs.
See “Nonvolatile Register Programming” on page 205 for more information
on programming Flash-memory-resident registers.
210
June 29, 2010
Texas Instruments-Advance Information