TM4C1237D5PZ Datasheet, PDF (529/1306 Pages) Texas Instruments – Tiva Microcontroller

Tiva^™ TM4C1237D5PZ Microcontroller
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 527). If the access
is a write access, the data contained in the Flash Memory Data (FMD) register (see page 528) 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 RW, 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
RW
RW
RW
RW
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
RW
Reset
0x0000
0x00
0
Description
Flash Memory Write Key
This field contains a write key, which is used to minimize the incidence
of accidental Flash memory writes. Depending on the value of the KEY
bit in the BOOTCFG register, the value 0xA442 or 0x71D5 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
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.
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.
See “Non-Volatile Register Programming” on page 517 for more
information on programming Flash-memory-resident registers.
June 12, 2014
529
Texas Instruments-Production Data