ISSUE 4.3 : November 1998
PUMA 68F16006/A-80/90/12/15
Sector Protection
The device features hardware sector protection. This feature will disable both program and erase operations
in any number of sectors (0 through 8). The sector protect feature is enabled using programming equipment at
the users site. The device is shipped with all sectors unprotected.
To activate this mode, the programming equipment must force VID on address pin A9 and control pin OE, and
CE=VIH. The sector adresses (A18, A17 and A16) should be set to the sector to be protected. Programming of
the protection circuitry begins on the falling edge of the WE pulse and is terminated with the rising edge of the
same. Sector addresses must be held constant during the WE pulse.
To verify programming of the protection equipment circuitry, the programming equipment must force VID on
address pin A9 with CE and OE at VIL and WE at VIH. Reading the device at a particular sector address (A16,
A17 and A18) while (A6,A1,A0) = (0,1,0) will produce 01H at data output D0 for a protected sector. Otherwise
the device will read 00H for unprotected sector. In this mode, the lower order addresses, except for A0, , A1
and A6 , are don't care. Address with A1=VIL are reserved for autoselect codes. If a verify of the sector protec-
tion circuitry were done at these addresses, the device would output the manufacturer and device codes
respectively.
It is also possible to determine if a sector is protected in the system by writing the autoselect command.
Performing a read operation at XX02H , where the higher order addresses (A16, A17, A18) are sector
addresses,(other addresses are a don't care) will produce 01H data if those sectors are protected. Otherwise
the devidce will read 00H for an unprotected sector.
Sector Address Table
A18
0
A17
0
A16
0
Address Range
000000h-0FFFFh
10000h-1FFFFh
SA0
SA1
SA2
0
0
1
0
1
0
20000h-2FFFFh
SA3
SA4
0
1
1
0
1
0
30000h-3FFFFh
40000h-4FFFFh
SA5
SA6
SA7
1
1
1
0
1
1
1
0
1
50000h-5FFFFh
60000h-6FFFFh
70000h-7FFFFh
Sector Unprotect
Sectors which have previously been protected from being programmed or erased may be unprotected using
the Sector Unprotect Algorithm. All sectors must be placed in the protection mode using the protection
algorithm before unprotection can proceed.
A special high voltage for unprotection VSP is defined to be 10V+/-0.5V.
The unprotection mode is entered by setting OE to VID or VSP, WE to VSP, A5 to VIH and A0=A9 to VIL. Unprotect
is invoked by applying to negative pulses on CE for a period of tWPP2
.
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MOSAIC [ MOSAIC ]
