Texas Instruments MSP430x1xx - Manual (Page 429)

Flash Memory Control Registers
C-17
Flash Memory
ACCVIFG bit2, Access violation interrupt flag
The access-violation interrupt flag is set when the flash memory
module is improperly accessed while a write or erase operation is
active. The violation situations are described in section C.2. When the
access-violation interrupt-enable bit is set, the interrupt-service
request is accepted and the program continues at the NMI
interrupt-vector address.
Reading the control registers will not set the ACCVIFG bit.
Note: The proper interrupt-enable bit ACCVIE is located in interrupt-
enable register IE1 of the special-function register. Software can
set the ACCVIFG bit; in this case, an NMI is also executed.
WAIT 012Ch, bit3, Wait. In the segment write mode the WAIT bit indicates that the flash
memory is ready to receive the (next) data for programming. The WAIT
bit is read only, but a write to the WAIT bit is allowed.
The WAIT bit is automatically reset if the SEGWRT bit is reset or the
LOCK bit is set. Segment-write operation is completed, and then the
WAIT bit returns to 1.
Condition, SEGWRT=1 (see Figure C-9):
After each successful write operation, the BUSY bit is reset to indicate
that another byte or word can be written (programmed). The BUSY bit
does not indicate the condition when the timing generator has
completed the entire programming. The high-voltage portion and
voltage generator remain active. The maximum time t
(CPT)
should not
be violated.
0: Segment-write operation has started and programming is in
progress.
1: Segment-write operation is active and programming of data is
completed. Waiting for the next data to be programmed.
Lock 012Ch, bit4, The Lock bit can be set during any write, erase of a segment, or
mass-erase request. The active sequence is completed normally. In
segment-write mode, if the Lock bit is set and SEGWRT and WAIT are
set, the SEGWRT and WAIT bits are reset and the mode ends
normally. The WAIT bit is 1 after segment-write mode has ended.
Software or hardware can control the Lock bit. If an access violation
occurs (see conditions described in paragraph C.1.1), the ACCVIFG
and the Lock bit are set.
0: Flash memory can be read, programmed, erased, and mass-
erased.
0: Flash memory can be read but not programmed, erased, or
mass-erased. A current program, erase, or mass-erase operation
is completed normally. The access-violation interrupt flag
ACCVIFG is set when the flash memory module is accessed while
the Lock bit is set.