ATmega3250 register table (also ATmega325, 645, 6450.)
  Walking along the table below fills the bits of a Register
7654 3210
---- ----
/0123456789ABCDEF/
0R0R1R2R3R4R5R6R7R8R9R10R11R12R13R14R150
1R16R17R18R19R20R21R22R23R24R25R26R27R28R29R30R311
2PINADDRAPORTAPINBDDRBPORTBPINCDDRCPORTCPINDDDRDPORTDPINEDDREPORTEPINF2
3DDRFPORTFPINGDDRGPORTGTIFR0TIFR1TIFR2EIFREIMSKGPIOR0EECR3
4EEDREEAR
EEARL
EEARHGTCCRTCCR0ATCNT0OCR0AGPIOR1GPIOR2SPCRSPSRSPDR4
5ACSROCDRSMCRMCUSRMCUCRSPMCSR5
6WDTCRCLKPRPRROSCCALEICRAPCMSK0PCMSK1PCMSK2TIMSK0TIMSK16
7TIMSK2PCMSK3ADC
ADCW
ADCL
ADCHADCSRAADCSRBADMUXDIDR0DIDR17
8TCCR1ATCCR1BTCCR1CTCNT1
TCNT1L
TCNT1HICR1
ICR1L
ICR1HOCR1A
OCR1AL
OCR1AHOCR1B
OCR1BL
OCR1BH8
99
AA
BTCCR2ATCNT2OCR2AASSRUSICRUSISRUSIDRB
CUCSR0AUCSR0BUCSR0CUBRR0
UBRR0L
UBRR0HUDR0C
DPINHDDRHPORTHPINJDDRJPORTJD
EE
FF
/0123456789ABCDEF/

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