ATmega168 Automotive Atmel Corporation, ATmega168 Automotive Datasheet - Page 261

• Manufacturer Part Number: ATmega168 Automotive
• Manufacturer: Atmel Corporation

Specifications of ATmega168 Automotive

• Flash (kbytes): 16 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 23
• Ext Interrupts: 24
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• 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): 1
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 150
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

23.1.6
7530I–AVR–02/10
Simple Assembly Code Example for a Boot Loader
Note that the RWWSB bit will always be read as zero in ATmega48. Nevertheless, it is recom-
mended to check this bit as shown in the code example, to ensure compatibility with devices
supporting Read-While-Write.
.equ
words
.org SMALLBOOTSTART
Write_page:
Wrloop:
;-the routine writes one page of data from RAM to Flash
; the first data location in RAM is pointed to by the Y pointer
; the first data location in Flash is pointed to by the Z-pointer
;-error handling is not included
;-the routine must be placed inside the Boot space
; (at least the Do_spm sub routine). Only code inside NRWW section can
; be read during Self-Programming (Page Erase and Page Write).
;-registers used: r0, r1, temp1 (r16), temp2 (r17), looplo (r24),
; loophi (r25), spmcrval (r20)
; storing and restoring of registers is not included in the routine
; register usage can be optimized at the expense of code size
;-It is assumed that either the interrupt table is moved to the Boot
; loader section or that the interrupts are disabled.
;
ldi
rcall
;
ldi
rcall
;
ldi
ldi
ld
ld
ldi
rcall
adiw
sbiw
brne
;
subi
sbci
ldi
rcall
;
ldi
Page Erase
re-enable the RWW section
transfer data from RAM to Flash page buffer
execute Page Write
re-enable the RWW section
PAGESIZEB = PAGESIZE*2
spmcrval, (1<<PGERS) | (1<<SELFPRGEN)
Do_spm
spmcrval, (1<<RWWSRE) | (1<<SELFPRGEN)
Do_spm
looplo, low(PAGESIZEB);init loop variable
loophi, high(PAGESIZEB);not required for PAGESIZEB<=256
r0, Y+
r1, Y+
spmcrval, (1<<SELFPRGEN)
Do_spm
ZH:ZL, 2
loophi:looplo, 2
Wrloop
ZL, low(PAGESIZEB)
ZH, high(PAGESIZEB) ;not required for PAGESIZEB<=256
spmcrval, (1<<PGWRT) | (1<<SELFPRGEN)
Do_spm
spmcrval, (1<<RWWSRE) | (1<<SELFPRGEN)
ATmega48/88/168 Automotive
;PAGESIZEB is page size in BYTES, not
;use subi for PAGESIZEB<=256
;restore pointer
261