ATMEGA48-20MMU Atmel, ATMEGA48-20MMU Datasheet - Page 25

• Manufacturer Part Number: ATMEGA48-20MMU
• Description: IC AVR MCU 4K FLASH 20MHZ 28QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA48-20MMU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 23
• Program Memory Size: 4KB (2K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• Processor Series: ATMEGA48x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 512 B
• Interface Type: 2-Wire/SPI/USART/Serial
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 23
• Number Of Timers: 3
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8-ch x 10-bit
• Package: 28MLF EP
• Device Core: AVR
• Family Name: ATmega
• Maximum Speed: 20 MHz
• Operating Supply Voltage: 3.3|5 V
• For Use With: ATSTK600-TQFP32 - STK600 SOCKET/ADAPTER 32-TQFPATSTK600 - DEV KIT FOR AVR/AVR32770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATAVRISP2 - PROGRAMMER AVR IN SYSTEMATJTAGICE2 - AVR ON-CHIP D-BUG SYSTEM
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7.6.4
7.6.5
7.6.6
2545S–AVR–07/10
GPIOR2 – General Purpose I/O Register 2
GPIOR1 – General Purpose I/O Register 1
GPIOR0 – General Purpose I/O Register 0
The next code examples show assembly and C functions for reading the EEPROM. The exam-
ples assume that interrupts are controlled so that no interrupts will occur during execution of
these functions.
Bit
0x2B (0x4B)
Read/Write
Initial Value
Bit
0x2A (0x4A)
Read/Write
Initial Value
Bit
0x1E (0x3E)
Read/Write
Initial Value
Assembly Code Example
C Code Example
EEPROM_read:
unsigned char EEPROM_read(unsigned int uiAddress)
{
}
; Wait for completion of previous write
sbic EECR,EEPE
rjmp EEPROM_read
; Set up address (r18:r17) in address register
out EEARH, r18
out EEARL, r17
; Start eeprom read by writing EERE
sbi EECR,EERE
; Read data from Data Register
in
ret
/* Wait for completion of previous write */
while(EECR & (1<<EEPE))
/* Set up address register */
EEAR = uiAddress;
/* Start eeprom read by writing EERE */
EECR |= (1<<EERE);
/* Return data from Data Register */
return EEDR;
;
r16,EEDR
MSB
MSB
MSB
R/W
R/W
R/W
7
0
7
0
7
0
R/W
R/W
R/W
6
0
6
0
6
0
R/W
R/W
R/W
5
0
5
0
5
0
R/W
R/W
R/W
4
0
4
0
4
0
R/W
R/W
R/W
3
0
3
0
3
0
R/W
R/W
R/W
ATmega48/88/168
2
0
2
0
2
0
R/W
R/W
R/W
1
0
1
0
1
0
LSB
R/W
LSB
R/W
LSB
R/W
0
0
0
0
0
0
GPIOR2
GPIOR1
GPIOR0
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