atmega161-4pi ATMEL Corporation, atmega161-4pi Datasheet - Page 124

• Manufacturer Part Number: atmega161-4pi
• Description: 8-bit Microcontroller With 16k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

Reading the Fuse and Lock
Bits
Reading the Signature Bytes
Parallel Programming
Characteristics
124
ATmega161(L)
The algorithm for reading the Fuse and Lock bits is as follows (refer to “Programming
the Flash” on page 120 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
3. Set OE to “0”, and BS to “1”. The status of the Lock bits can now be read at DATA
4. Set OE to “1”.
The algorithm for reading the Signature bytes is as follows (refer to “Programming the
Flash” on page 120 for details on command and address loading):
1. A: Load Command “0000 1000”.
2. C: Load Address Low Byte ($00 - $02).
3. Set OE to “1”.
Figure 79. Parallel Programming Timing
(DATA, XA0/1, BS1)
DATA (“0” means programmed).
Bit 6 = BOOTRST Fuse bit
Bit 5 = SPIEN Fuse bit
Bit 4 = SUT Fuse bit
Bit 3 = “1”. This bit is reserved and must be left unprogrammed (“1”).
Bits 2 - 0 = CKSEL2..0 Fuse bits
(“0” means programmed).
Bit 5 = Boot Lock Bit12
Bit 4 = Boot Lock Bit11
Bit 3 = Boot Lock Bit02
Bit 2 = Boot Lock Bit01
Bit 1 = Lock Bit2
Bit 0 = Lock Bit1
Set OE to “0”, and BS to “0”. The selected Signature byte can now be read at DATA.
Data & Control
RDY/BSY
PAGEL
XTAL1
DATA
WR
OE
t
t
BVXH
DVXH
t
t
XHXL
PHPL
t
t
t
t
t
XLOL
XLDX
XLWL
PLBX
PLWL
t
BVWL
t
WLWH
WLRL
t
OLDV
t
t
WLRH
OHDZ
t
RHBX
1228D–AVR–02/07