AT90CAN128-16AE ATMEL Corporation, AT90CAN128-16AE Datasheet - Page 33

• Manufacturer Part Number: AT90CAN128-16AE
• Description: 8-bit Avr Microcontroller With 128K Bytes of Isp Flash And CAN Controller.flash (Kbytes) 128 Vcc (V) 2.7-5.5 EEPROM (Kbytes) 4 SRAM (bytes) 4K CAN (mess. Obj.) 15
• Manufacturer: ATMEL Corporation

4250C–CAN–03/04
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. The example code assumes that the part specific header file is included.
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)
AT90CAN128
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