at88sa100s ATMEL Corporation, at88sa100s Datasheet - Page 15

• Manufacturer Part Number: at88sa100s
• Description: Battery Authentication Chip
• Manufacturer: ATMEL Corporation

4.3.
8558B–SMEM–09/09
BurnFuse
Burns one of the 88 user accessible fuse bits.
The values in fuses #88-127 are reserved for Fuse MfrID and Fuse SN and cannot be blown via this command. All
addresses above 0x57 (87) will result in an error.
Fuses, with the exception of those initialized by Atmel, have a value of 1 on shipment from the Atmel factory and
transition to a 0 when they are burned.
Fuse bits #0 through #7 of the fuse array are word lock bits. Burning one of these has the effect of locking the
corresponding 16 bit word within Fuse. Bit 0 locks fuses 0-15, bit 1 locks fuses 16-31 and so on. If bit 0 is burned, then
the value of the lock bits can no longer be changed. The values of lock bits 6 & 7 are ignored by the chip.
The power supply pin must meet the V
reliably. If Vcc is greater than 4.5V, then the BurnTime parameter should be set to 0x00 and the internal burn time will
be 250μs. If Vcc is less than 4.5V but greater than V
the internal burn time will be up to 190ms. The chip does NOT internally check the supply voltage level.
There is a very small interval during t
must not be removed during this interval and the watchdog timer must not be allowed to expire during this interval, or
the fuse may end up in a state where it reads as un-burned but cannot be burned.
Table 13.
Table 14.
Opcode
Param1
Param2
Data
Success
Name
Input Parameters
Output Parameters
BURNFUSE
FuseNum
BurnTime
–
Name
Size
1
EXEC_BURN
Upon successful completion, a value of 0 will be returned by the device.
BURN
specification during the entire BurnFuse command in order to burn fuses
Size
1
1
2
0
when the fuse element is actually being burned. The power supply
BURN
0x04
Which bit within fuse array, minimum value is 0, and
maximum value is 87.
Must be 0x00 00 if Vcc > 4.5V, must be 0x80 00 otherwise.
then the BurnTime parameter should be set to 0x8000 and
AT88SA100S [ Preliminary]
Notes
Notes
15