ATMEGA128A-ANR Atmel, ATMEGA128A-ANR Datasheet - Page 33

• Manufacturer Part Number: ATMEGA128A-ANR
• Description: IC MCU AVR 128K FLASH 64TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA128A-ANR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 128KB (64K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 4K 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: 64-TQFP
• Core: AVR8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7.6.4
8151H–AVR–02/11
MCUCR - MCU Control Register
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 7 – SRE: External SRAM/XMEM Enable
Writing SRE to one enables the External Memory Interface.The pin functions AD7:0, A15:8,
ALE, WR, and RD are activated as the alternate pin functions. The SRE bit overrides any pin
direction settings in the respective data direction registers. Writing SRE to zero, disables the
External Memory Interface and the normal pin and data direction settings are used.
• Bit 6 – SRW10: Wait-state Select Bit
For a detailed description in non-ATmega103 compatibility mode, see common description for
the SRWn bits below (XMCRA description). In ATmega103 compatibility mode, writing SRW10
Bit
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,EEWE
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<<EEWE))
/* Set up address register */
EEAR = uiAddress;
/* Start eeprom read by writing EERE */
EECR |= (1<<EERE);
/* Return data from data register */
return EEDR;
;
r16,EEDR
SRE
R/W
7
0
SRW10
R/W
6
0
R/W
SE
5
0
SM1
R/W
4
0
SM0
R/W
3
0
SM2
R/W
2
0
IVSEL
ATmega128A
R/W
1
0
IVCE
R/W
0
0
MCUCR
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