ATmega6450 Atmel Corporation, ATmega6450 Datasheet - Page 19

• Manufacturer Part Number: ATmega6450
• Manufacturer: Atmel Corporation

Specifications of ATmega6450

• Flash (kbytes): 64 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 69
• Ext Interrupts: 25
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 4
• Eeprom (bytes): 2048
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

8.2
8.2.1
2570N–AVR–05/11
SRAM Data Memory
Data Memory Access Times
Figure 8-2 on page 19
organized.
The Atmel ATmega325/3250/645/6450 is a complex microcontroller with more peripheral units
than can be supported within the 64 locations reserved in the 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.
The lower 2304/4352 data memory locations address both the Register File, the I/O memory,
Extended I/O memory, and the internal data SRAM. The first 32 locations address the Register
File, the next 64 location the standard I/O memory, then 160 locations of Extended I/O memory,
and the next 2048/4096 locations address the internal data SRAM.
The five different addressing modes for the data memory cover: Direct, Indirect with Displace-
ment, Indirect, Indirect with Pre-decrement, and Indirect with Post-increment. In the Register
File, registers R26 to R31 feature the indirect addressing pointer registers.
The direct addressing reaches the entire data space.
The Indirect with Displacement mode reaches 63 address locations from the base address given
by the Y- or Z-register.
When using register indirect addressing modes with automatic pre-decrement and post-incre-
ment, the address registers X, Y, and Z are decremented or incremented.
The 32 general purpose working registers, 64 I/O Registers, 160 Extended I/O Registers, and
the 2,048 bytes of internal data SRAM in the Atmel ATmega325/3250/645/6450 are all accessi-
ble through all these addressing modes. The Register File is described in
Register File” on page
Figure 8-2.
This section describes the general access timing concepts for internal memory access. The
internal data SRAM access is performed in two clk
Data Memory Map
13.
shows how the Atmel ATmega325/3250/645/6450 SRAM Memory is
160 Ext I/O Reg.
64 I/O Registers
Data Memory
Internal SRAM
32 Registers
(2048 x 8)/
(4096 x 8)
ATmega325/3250/645/6450
0x08FF/0x10FF
0x0000 - 0x001F
0x0020 - 0x005F
0x0060 - 0x00FF
0x0100
CPU
cycles as described in
“General Purpose
Figure
8-3.
19