CHAPTER 3 COMMANDS
Information M14914EJ4V0IF
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3.11 Sector Group Unprotect
This command performs sector group unprotect.
Sector group unprotect is performed for all sector group. Unprotect cannot be performed for specific sector group.
Moreover, all sector groups must be protected priors to unprotect.
The device enters the sector group unprotect mode by applying VID to /RESET and writing 60H to any address.
If unprotected sector group exist, first perform sector group protection for these sector groups. To protect a sector
group, input the sector group address of the sector group to be protected to the sector group address input pin, input
(A6, A1, A0) = (VIL, VIH, VIL), and write 60H (refer to 3.10 Sector Group Protection).
Sector group unprotect is started by inputting (A6, A1, A0) = (VIH, VIH, VIL), and writing 60H to any address.
Following a timeout of 15 ms, sector group unprotect is completed.
Unprotect verification must be performed for each sector group.
The device enters the sector group unprotect verification mode by inputting the sector group address to input pin of
sector group address and writing 40H, with input (A6, A1, A0) = (VIH, VIH, VIL).
If reading is performed in this state, the sector group unprotect verification result is output to I/O0. If the verified
sector group is unprotected, "0" is output to I/O0. If "0" is not output to I/O0, this means that unprotect failed, so
perform sector group unprotect again.
For the flow chart, refer to Figure 7-5. Sector Group Unprotect Flow Chart.
3.12 Query
The dual operation flash memory conforms to CFI (Common Flash memory Interface). CFI enables information
about a device such as the device specifications, memory density, and supply voltage to be read. Therefore, the
software of the host system can support the software algorithm of a specific vendor used by a device by using the
CFI. For details, refer to the CFI specifications.
By writing the Query command (98H) and giving an address, the device information corresponding to that address
can be read (refer to the CFI Code List in each Data Sheet). If the device information is read in the WORD mode (16
bits), the upper bytes of data (I/O15 to I/O8) are "0".
To end the Query mode, writes the read / reset command.
3.13 Extra One Time Protect Sector Entry
The dual operation flash memory has a sector area that has One Time Protect function. This area does not allow
code that has been written to the area to be changed. This area can be programmed or erased until it is protected.
Once it has been protected, however, protection can never be canceled. Therefore, care must be exercised when
using this area.
The Extra One Time Protect Sector area has a density of 64 Kbytes and exits at the same addresses as the
8K bytes sector. These addresses are 3F0000H to 3FFFFFH for top boot in the BYTE mode (1F8000H to
1FFFFFH in the WORD mode), and 000000H to 00FFFFH for bottom boot in the BYTE mode (000000H to 007FFFH
in the WORD mode). Because boot block areas (8K bytes x 8 sectors) usually appear in the areas of these
addresses, the Extra One Time Protect Sector entry command sequence must be written to enter them as the Extra
One Time Protect Sector area. The status in which the Extra One Time Protect Sector area appears is the Extra One
Time Protect Sector mode.
In the Extra One Time Protect Sector mode, the other sectors, except the boot block area, can be read. In addition,
the Extra One Time Protect Sector area can be read, programmed, or erased in this mode. To exit from the Extra
One Time Protect Sector mode, the Extra One Time Protect Sector Reset command sequence must be written.