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Fuse settings when shipping a device

2009-09-04 by Chuck Hackett

I’d like to verify my understanding of the proper fuse settings for a device
(ATMega16) to be shipped as a final product.  

I’m “shipping” some parts now but it’s a “friendly” beta environment so some
settings will be relaxed.  My understanding is that, just prior to shipping,
I should:

For a "friendly" environment (allows application area to be reprogrammed via

					the boot loader, not worried about
code protection):
	OCDEN:	Disable to reduce power consumption in low power sleep modes
	JTAGEN:	Disable, no OC level debugging expected in the field
	SPIEN:	Disable, no OC level debugging expected in the field
	BOOTRST:	Enable to allow field upgrading
	LB:		Programming & verification enabled
	BLB0:		SPM & LPM permitted in application section (for
field upgrades)
	BLB1:		SPM prohibited in boot section (to protect boot
loader from 
			being overwritten, LPM allowed-see BLB0 below)
	

For a "hostile" environment (to protect the code):
	OCDEN:	Disable to reduce power consumption in low power sleep modes
	JTAGEN:	Disable to protect the code
	SPIEN:	Disable to protect the code
	BOOTRST:	Disable to protect the code (no field upgrading)
	LB:		Programming & verification disabled
	BLB0:		SPM prohibited in application section (I assume that
LPM 
			must be left enabled to use flash-based constant
data?)
	BLB1:		SPM prohibited in boot section (LPM: see BLB0)

Did I miss anything?
 
Cheers,

Chuck Hackett
"Good judgment comes from experience, experience comes from bad judgment"
7.5" gauge Union Pacific Northern (4-8-4) 844
http://www.whitetrout.net/Chuck

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