Rainbow Electronics ATmega103L - Manual (Page 100)

ATmega603/103
100
Reading the Fuse and Lock Bits
The algorithm for reading the Fuse and Lock bits is as follows (refer to Programming the Flash for details on Command
loading):
1. A: Load Command ‘0000 0100’.
2. Set OE to ‘0’, and BS to ‘0’. The status of the Fuse bits can now be read at DATA (‘0’ means programmed).
Bit 5 = SPIEN Fuse bit
Bit 3 = EESAVE Fuse bit
Bit 1 = SUT1 Fuse bit
Bit 0 = SUT0 Fuse bit
Set OE to ‘0’, and BS to ‘1’. The status of the Lock bits can now be read at DATA (‘0’ means programmed).
Bit 2 = Lock Bit2
Bit 1 = Lock Bit1
3. Set OE to ‘1’.
Reading the Signature Bytes
The algorithm for reading the Signature bytes is as follows (refer to Programming the Flash for details on Command and
Address loading):
1. A: Load Command ‘0000 1000’.
2. C: Load Address Low Byte ($00 - $02).
Set OE to ‘0’, and BS to ‘0’. The selected Signature byte can now be read at DATA.
3. Set OE to ‘1’.
Parallel Programming Characteristics
Figure 76. Parallel Programming Timing
Data & Contol
(DATA, XA0/1, BS1)
DATA
W
rite
Read
XTAL1 t
XHXL
t
WLWH
t
DVXH
t
XLOL
t
OLDV
t
XLDX
t
PLWL
t
WHRL
t
WLRH
WR
RDY/BSY
OE
PAGEL t
PHPL
t
PLBX
t
BVXH
t
XLWL
t
RHBX
t
OHDZ
t
BVWL