ATMEGA16-16AQ Atmel, ATMEGA16-16AQ Datasheet - Page 254

MCU AVR 16K FLASH 16MHZ 44-TQFP

ATMEGA16-16AQ

Manufacturer Part Number
ATMEGA16-16AQ
Description
MCU AVR 16K FLASH 16MHZ 44-TQFP
Manufacturer
Atmel
Series
AVR® ATmegar
Datasheet

Specifications of ATMEGA16-16AQ

Core Processor
AVR
Core Size
8-Bit
Speed
16MHz
Connectivity
I²C, SPI, UART/USART
Peripherals
Brown-out Detect/Reset, POR, PWM, WDT
Number Of I /o
32
Program Memory Size
16KB (8K x 16)
Program Memory Type
FLASH
Eeprom Size
512 x 8
Ram Size
1K x 8
Voltage - Supply (vcc/vdd)
4.5 V ~ 5.5 V
Data Converters
A/D 8x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
44-TQFP, 44-VQFP
For Use With
ATSTK600-TQFP44 - STK600 SOCKET/ADAPTER 44-TQFPATSTK500 - PROGRAMMER AVR STARTER KIT
Lead Free Status / RoHS Status
Lead free / RoHS Compliant

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
ATMEGA16-16AQ
Manufacturer:
Atmel
Quantity:
10 000
Part Number:
ATMEGA16-16AQR
Manufacturer:
Atmel
Quantity:
10 000
Setting the Boot
Loader Lock Bits by
SPM
EEPROM Write
Prevents Writing to
SPMCR
Reading the Fuse and
Lock Bits from
Software
Preventing Flash
Corruption
2466T–AVR–07/10
To set the Boot Loader Lock bits, write the desired data to R0, write “X0001001” to SPMCR and
execute SPM within four clock cycles after writing SPMCR. The only accessible Lock bits are the
Boot Lock bits that may prevent the Application and Boot Loader section from any software
update by the MCU.
See
access.
If bits 5..2 in R0 are cleared (zero), the corresponding Boot Lock bit will be programmed if an
SPM instruction is executed within four cycles after BLBSET and SPMEN are set in SPMCR.
The Z-pointer is don’t care during this operation, but for future compatibility it is recommended to
load the Z-pointer with $0001 (same as used for reading the Lock bits). For future compatibility It
is also recommended to set bits 7, 6, 1, and 0 in R0 to “1” when writing the Lock bits. When pro-
gramming the Lock bits the entire Flash can be read during the operation.
Note that an EEPROM write operation will block all software programming to Flash. Reading the
Fuses and Lock bits from software will also be prevented during the EEPROM write operation. It
is recommended that the user checks the status bit (EEWE) in the EECR Register and verifies
that the bit is cleared before writing to the SPMCR Register.
It is possible to read both the Fuse and Lock bits from software. To read the Lock bits, load the
Z-pointer with $0001 and set the BLBSET and SPMEN bits in SPMCR. When an LPM instruction
is executed within three CPU cycles after the BLBSET and SPMEN bits are set in SPMCR, the
value of the Lock bits will be loaded in the destination register. The BLBSET and SPMEN bits
will auto-clear upon completion of reading the Lock bits or if no LPM instruction is executed
within three CPU cycles or no SPM instruction is executed within four CPU cycles. When BLB-
SET and SPMEN are cleared, LPM will work as described in the Instruction set Manual.
The algorithm for reading the Fuse Low bits is similar to the one described above for reading the
Lock bits. To read the Fuse Low bits, load the Z-pointer with $0000 and set the BLBSET and
SPMEN bits in SPMCR. When an LPM instruction is executed within three cycles after the BLB-
SET and SPMEN bits are set in the SPMCR, the value of the Fuse Low bits (FLB) will be loaded
in the destination register as shown below. Refer to
description and mapping of the Fuse Low bits.
Similarly, when reading the Fuse High bits, load $0003 in the Z-pointer. When an LPM instruc-
tion is executed within three cycles after the BLBSET and SPMEN bits are set in the SPMCR,
the value of the Fuse High bits (FHB) will be loaded in the destination register as shown below.
Refer to
Fuse and Lock bits that are programmed, will be read as zero. Fuse and Lock bits that are
unprogrammed, will be read as one.
During periods of low V
low for the CPU and the Flash to operate properly. These issues are the same as for board level
systems using the Flash, and the same design solutions should be applied.
Bit
R0
Bit
Rd
Bit
Rd
Bit
Rd
Table 96
Table 105 on page 260
and
FHB7
FLB7
7
1
7
7
7
Table 97
FHB6
FLB6
CC,
6
6
6
1
6
the Flash program can be corrupted because the supply voltage is too
for how the different settings of the Boot Loader bits affect the Flash
BLB12
BLB12
FHB5
FLB5
for detailed description and mapping of the Fuse High bits.
5
5
5
5
BLB11
BLB11
FHB4
FLB4
4
4
4
4
BLB02
BLB02
FHB3
FLB3
3
3
3
3
BLB01
BLB01
Table 106 on page 261
FHB2
FLB2
2
2
2
2
FHB1
FLB1
LB2
1
1
1
1
1
ATmega16(L)
FHB0
FLB0
LB1
0
1
0
0
0
for a detailed
254

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