Rainbow Electronics ATmega128L - Manual (Page 290)

290
ATmega128(L)
2467B–09/01
Figure 139. Mapping Between BS1, BS2 and the Fuse- and Lock Bits During Read
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. B: Load Address Low Byte ($00 - $02).
3. Set OE to “0”, and BS1 to “0”. The selected Signature byte can now be read at
DATA.
4. Set OE to “1”.
Reading the Calibration Byte The algorithm for reading the Calibration byte is as follows (refer to Programming the
Flash for details on Command and Address loading):
1. A: Load Command “0000 1000”.
2. B: Load Address Low Byte, $00.
3. Set OE to “0”, and BS1 to “1”. The Calibration byte can now be read at DATA.
4. Set OE to “1”.
Parallel Programming
Characteristics Figure 140. Parallel Programming Timing, Including some General Timing
Requirements
Lock bits 0
1
BS2
Fuse high byte
0
1
BS1
DATA
Fuse Low Byte 0
1
BS2
Extended Fuse byte
Data & Contol
(DATA, XA0/1, BS1, BS2)
XTAL1
t
XHXL
t
WL WH
t
DVXH
t
XLDX
t
PLWL
t
WLRH
WR
RDY/BSY
PAGEL t
PHPL
t
PLBX
t
BVPH
t
XLWL
t
WLBX
t
BVWL
WLRL