ATmega64A Atmel Corporation, ATmega64A Datasheet - Page 28

• Manufacturer Part Number: ATmega64A
• Manufacturer: Atmel Corporation

Specifications of ATmega64A

• Flash (kbytes): 64 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 53
• Ext Interrupts: 8
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 2
• 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: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 4
• Output Compare Channels: 8
• Input Capture Channels: 2
• Pwm Channels: 7
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

7.5.8
8160C–AVR–07/09
Using all 64KB Locations of External Memory
0x1100 to 0x90FF. This is illustrated in
ATmega103 compatibility mode, configuration A to the non-compatible mode.
When the device is set in ATmega103 compatibility mode, the internal address space is 4,096
bytes. This implies that the first 4,096 bytes of the external memory can be accessed at
addresses 0x8000 to 0x8FFF. To the Application software, the external 32 KB memory will
appear as one linear 32 KB address space from 0x1000 to 0x8FFF.
Figure 7-10. Address Map with 32 KB External Memory
Since the external memory is mapped after the internal memory as shown in
60KB of external memory is available by default (address space 0x0000 to 0x10FF is reserved
for internal memory). However, it is possible to take advantage of the entire external memory by
masking the higher address bits to zero. This can be done by using the XMMn bits and con-
trolled by software the most significant bits of the address. By setting Port C to output 0x00, and
releasing the most significant bits for normal Port Pin operation, the Memory Interface will
address 0x0000 - 0x1FFF. See code examples below.
0x0000
0x10FF
0x1100
0x7FFF
0x8000
0x90FF
0x9100
0xFFFF
AVR Memory Map
Internal Memory
External
(Unused)
Memory
Memory Configuration A
External 32K SRAM
0x0000
0x10FF
0x1100
0x7FFF
Figure
7-10. Memory configuration B refers to the
0x0000
0x0FFF
0x1000
0x7FFF
0x8000
0x8FFF
0x9000
0xFFFF
AVR Memory Map
Internal Memory
External
(Unused)
Memory
Memory Configuration B
ATmega64A
External 32K SRAM
Figure
0x0000
0x0FFF
0x1000
0x7FFF
7-4, only
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