ATMEGA128A-ANR Atmel, ATMEGA128A-ANR Datasheet - Page 29

• 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

8151H–AVR–02/11
Note:
Care must be exercised using this option as most of the memory is masked away.
Assembly Code Example
C Code Example
#define OFFSET 0x2000
void XRAM_example(void)
{
unsigned char *p = (unsigned char *) (OFFSET + 1);
DDRC = 0xFF;
PORTC = 0x00;
XMCRB = (1<<XMM1) | (1<<XMM0);
*p = 0xaa;
XMCRB = 0x00;
*p = 0x55;
}
; OFFSET is defined to 0x2000 to ensure
; external memory access
; Configure Port C (address high byte) to
; output 0x00 when the pins are released
; for normal Port Pin operation
ldi
out
ldi
out
; release PC7:5
ldi
sts
; write 0xAA to address 0x0001 of external
; memory
ldi
sts
; re-enable PC7:5 for external memory
ldi
sts
; store 0x55 to address (OFFSET + 1) of
; external memory
ldi
sts
1. See “About Code Examples” on page 8.
r16, 0xFF
DDRC, r16
r16, 0x00
PORTC, r16
r16, (1<<XMM1)|(1<<XMM0)
XMCRB, r16
r16, 0xaa
0x0001+OFFSET, r16
r16, (0<<XMM1)|(0<<XMM0)
XMCRB, r16
r16, 0x55
0x0001+OFFSET, r16
(1)
(1)
ATmega128A
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