ATMEGA325PV_14 Datasheet, PDF (283/364 Pages) ATMEL Corporation – High Performance, Low Power AVR

ATmega325P/3250P
Figure 25-6. Mapping Between BS1, BS2 and the Fuse and Lock Bits During Read
Fuse Low Byte
0
Extended Fuse Byte
1
BS2
Lock Bits
0
0
DATA
1
Fuse High Byte
1
BS1
BS2
25.6.13 Reading the Signature Bytes
25.6.14
The algorithm for reading the Signature bytes is as follows (refer to ”Programming the Flash” on
page 277 for details on Command and Address loading):
1. A: Load Command “0000 1000”.
2. B: Load Address Low Byte (0x00 - 0x02).
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” on
page 277 for details on Command and Address loading):
25.6.15
1. A: Load Command “0000 1000”.
2. B: Load Address Low Byte, 0x00.
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 25-7. Parallel Programming Timing, Including some General Timing Requirements
XTAL1
Data & Contol
(DATA, XA0/1, BS1, BS2)
PAGEL
WR
t_DVXH
t_XHXL
t_XLWL
t_XLDX
t_BVPH
t_PHPL
t_PLBX t _BVWL
t_PLWL
t_WLWH
WLRL
t_WLBX
RDY/BSY
t_WLRH
8023F–AVR–07/09
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