6 general purpose i/o registers, 1 gpior0 - general purpose io register 0, 2 gpior1 - general purpose io register 1 – Rainbow Electronics ATmega128RFA1 User Manual
Page 26: 3 gpior2 - general purpose i/o register 2, 7 other port registers, Atmega128rfa1
26
8266A-MCU Wireless-12/09
ATmega128RFA1
8.6 General Purpose I/O Registers
The ATmega128RFA1 contains three General Purpose I/O Registers. These registers
can be used for storing any information, and they are particularly useful for storing
global variables and Status Flags. General Purpose I/O Registers within the address
range 0x00 – 0x1F are directly bit-accessible using the SBI, CBI, SBIS, and SBIC
instructions.
8.6.1 GPIOR0 – General Purpose IO Register 0
Bit
7
6
5
4
3
2
1
0
$1E ($3E)
GPIOR07:00
GPIOR0
Read/Write
RW
RW
RW
RW
RW
RW
RW
RW
Initial Value
0
0
0
0
0
0
0
0
The three General Purpose I/O Registers can be used for storing any information.
•
Bit 7:0 – GPIOR07:00 - General Purpose I/O Register 0 Value
8.6.2 GPIOR1 – General Purpose IO Register 1
Bit
7
6
5
4
3
2
1
0
$2A ($4A)
GPIOR17:10
GPIOR1
Read/Write
RW
RW
RW
RW
RW
RW
RW
RW
Initial Value
0
0
0
0
0
0
0
0
The three General Purpose I/O Registers can be used for storing any information.
•
Bit 7:0 – GPIOR17:10 - General Purpose I/O Register 1 Value
8.6.3 GPIOR2 – General Purpose I/O Register 2
Bit
7
6
5
4
3
2
1
0
$2B ($4B)
GPIOR27:20
GPIOR2
Read/Write
RW
RW
RW
RW
RW
RW
RW
RW
Initial Value
0
0
0
0
0
0
0
0
The three General Purpose I/O Registers can be used for storing any information.
•
Bit 7:0 – GPIOR27:20 - General Purpose I/O Register 2 Value
8.7 Other Port Registers
The inherited control registers of missing ports located in the I/O space are kept in the
ATmega128RFA1. They can be used as general purpose I/O registers for storing any
information. Registers placed in the address range 0x00 – 0x1F are directly bit-
accessible using the SBI, CBI, SBIS and SBIC instructions.