ATMEGA8_14 Datasheet, PDF (227/331 Pages) ATMEL Corporation – High-performance, Low-power Atmel

ATmega8(L)
Reading the Signature
Bytes
The algorithm for reading the Signature bytes is as follows (refer to “Programming the Flash” on
page 222 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 bytes is as follows (refer to “Programming the Flash” on
page 222 for details on Command and Address loading):
1. A: Load Command “0000 1000”
2. B: Load Address Low byte, (0x00 - 0x03)
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 109. Parallel Programming Timing, Including some General Timing Requirements
XTAL1
Data & Contol
(DATA, XA0/1, BS1, BS2)
PAGEL
WR
RDY/BSY
t _DVXH
t _XHXL
t _XLWL
t _XLDX
t _BVPH
t _PHPL
t _PLBX t _BVWL
t _PLWL
t _{WL WH}
WLRL
t _WLBX
t _WLRH
Figure 110. Parallel Programming Timing, Loading Sequence with Timing Requirements⁽¹⁾
LOAD ADDRESS
(LOW BYTE)
LOAD DATA
(LOW BYTE)
LOAD DATA LOAD DATA
(HIGH BYTE)
LOAD ADDRESS
(LOW BYTE)
XTAL1
t _XLXH
t_XLPH
t_PLXH
BS1
PAGEL
DATA
ADDR0 (Low Byte)
DATA (Low Byte)
DATA (High Byte)
ADDR1 (Low Byte)
XA0
XA1
Note: 1. The timing requirements shown in Figure 109 (that is, t_DVXH, t_XHXL, and t_XLDX) also apply to
loading operation
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