Datasheet

285
ATmega48/88/168 Automotive [DATASHEET]
7530K–AVR–07/14
29. Register Summary
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page
(0xFF) Reserved – – – – – – – –
(0xFE) Reserved
– – – – – – – –
(0xFD) Reserved
– – – – – – – –
(0xFC) Reserved
– – – – – – – –
(0xFB) Reserved
– – – – – – – –
(0xFA) Reserved
– – – – – – – –
(0xF9) Reserved
– – – – – – – –
(0xF8) Reserved
– – – – – – – –
(0xF7) Reserved
– – – – – – – –
(0xF6) Reserved
– – – – – – – –
(0xF5) Reserved
– – – – – – – –
(0xF4) Reserved
– – – – – – – –
(0xF3) Reserved
– – – – – – – –
(0xF2) Reserved
– – – – – – – –
(0xF1) Reserved
– – – – – – – –
(0xF0) Reserved
– – – – – – – –
(0xEF) Reserved
– – – – – – – –
(0xEE) Reserved
– – – – – – – –
(0xED) Reserved
– – – – – – – –
(0xEC) Reserved
– – – – – – – –
(0xEB) Reserved
– – – – – – – –
(0xEA) Reserved
– – – – – – – –
(0xE9) Reserved
– – – – – – – –
(0xE8) Reserved
– – – – – – – –
(0xE7) Reserved
– – – – – – – –
(0xE6) Reserved
– – – – – – – –
(0xE5) Reserved
– – – – – – – –
(0xE4) Reserved
– – – – – – – –
(0xE3) Reserved
– – – – – – – –
(0xE2) Reserved
– – – – – – – –
(0xE1) Reserved
– – – – – – – –
(0xE0) Reserved
– – – – – – – –
(0xDF) Reserved
– – – – – – – –
Notes: 1. For compatibility with future devices, reserved bits should be written to zero if accessed. Reserved I/O memory
addresses should never be written.
2. I/O registers within the address range 0x00 - 0x1F 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.
3. Some of the status flags are cleared by writing a logical one to them. Note that, unlike most other AVR
®
, the CBI and
SBI instructions will only operate on the specified bit, and can therefore be used on registers containing such status
flags. The CBI and SBI instructions work with registers 0x00 to 0x1F only.
4. When using the I/O specific commands IN and OUT, the I/O addresses 0x00 - 0x3F must be used. When addressing
I/O registers as data space using LD and ST instructions, 0x20 must be added to these addresses. The
ATmega48/88/168 is a complex microcontroller with more peripheral units than can be supported within the 64 location
reserved in opcode for the IN and OUT instructions. For the extended I/O space from 0x60 - 0xFF in SRAM, only the
ST/STS/STD and LD/LDS/LDD instructions can be used.
5. Only valid for Atmel
®
ATmega88/168