Table of Contents
Advertisement
23.5
Verifying Automatic Algorithm Execution Status
The flash memory contains the hardware for posting the internal flash memory
operating status or the flash memory operation completion, because the automatic
algorithm executes the sequence of data writing/deleting procedures. This automatic
algorithm can verify the internal flash memory operating status, depending on the
following hardware sequence.
■ Hardware Sequence Flag
The hardware sequence flag consists of the four flag bits, DQ7, DQ6, DQ5, and DQ3. These flag bits have
the data polling flag (DQ7) function, toggle bit flag (DQ6) function, time limit exceeded flag (DQ5)
function, and sector deletion timer flag (DQ3) function, respectively. These functions can verify whether
the write/chip sector deletion is terminated or whether the deletion code write is valid.
The hardware sequence flag can be referenced by accessing/reading the address of the target sector in the
flash memory, after setting the command sequence (see "23.4 Method of Starting the Automatic Algorithm
in Flash Memory"). Table 23.5-1 indicates the hardware sequence flag bit allocation.
Table 23.5-1 Hardware Sequence Flag Bit Allocation
Bit no.
7
Hardware
DQ7
sequence flag
It can be determined whether automatic write/chip sector deletion is being performed, depending on the end
of write processing, by checking the hardware sequence flag or the RDY bit in the flash memory control
register (FMCS). After the write/delete operation is terminated, the flash memory is returned to the read/
reset status. To actually create a program, it should be verified whether automatic write/delete operation is
terminated, depending on any flag, and the next operation such as the data reading should be executed.
Also, it can be verified whether the second sector deletion code write command or later commands are
valid, depending on the hardware sequence flag. The following explains the hardware sequence flags.
Table 23.5-2 lists the hardware sequence flag functions.
6
5
DQ6
DQ5
CHAPTER 23 512K / 1024K BIT FLASH MEMORY
4
3
-
DQ3
2
1
0
-
-
-
593
Advertisement
Table of Contents
