ATMEGA16-16AU SL602 Atmel, ATMEGA16-16AU SL602 Datasheet - Page 23

• Manufacturer Part Number: ATMEGA16-16AU SL602
• Manufacturer: Atmel

I/O Memory
2466T–AVR–07/10
EEPROM data corruption can easily be avoided by following this design recommendation:
The I/O space definition of the ATmega16 is shown in
All ATmega16 I/Os and peripherals are placed in the I/O space. The I/O locations are accessed
by the IN and OUT instructions, transferring data between the 32 general purpose working regis-
ters and the I/O space. I/O Registers within the address range $00 - $1F are directly bit-
accessible using the SBI and CBI instructions. In these registers, the value of single bits can be
checked by using the SBIS and SBIC instructions. Refer to the Instruction Set section for more
details. When using the I/O specific commands IN and OUT, the I/O addresses $00 - $3F must
be used. When addressing I/O Registers as data space using LD and ST instructions, $20 must
be added to these addresses.
For compatibility with future devices, reserved bits should be written to zero if accessed.
Reserved I/O memory addresses should never be written.
Some of the Status Flags are cleared by writing a logical one to them. Note that the CBI and SBI
instructions will operate on all bits in the I/O Register, writing a one back into any flag read as
set, thus clearing the flag. The CBI and SBI instructions work with registers $00 to $1F only.
The I/O and Peripherals Control Registers are explained in later sections.
Keep the AVR RESET active (low) during periods of insufficient power supply voltage. This
can be done by enabling the internal Brown-out Detector (BOD). If the detection level of the
internal BOD does not match the needed detection level, an external low V
tion circuit can be used. If a reset occurs while a write operation is in progress, the write
operation will be completed provided that the power supply voltage is sufficient.
“Register Summary” on page
ATmega16(L)
CC
Reset Protec-
331.
23