Jameco-electronics Rabbit 3000 Manuel d'utilisateur Page 323

  • Télécharger
  • Ajouter à mon manuel
  • Imprimer
  • Page
    / 349
  • Table des matières
  • MARQUE LIVRES
  • Noté. / 5. Basé sur avis des utilisateurs
Vue de la page 322
314 Rabbit 3000 Microprocessor
B.1.14 Quadrature Decoder Improvements
The quadrature decoder counters can now be expanded to 10 bits instead of 8 bits. This is
controlled by bit 5 in QDCR, listed in Table B-28. The additional two bits can be read in
the QDCxHR registers, listed in Table B-29.
NOTE: Bit 5 of QDCR was always written with a zero in the original Rabbit 3000 chip.
Table B-28. Quadrature Decoder Control Register
Quadrature Decoder Control Register (QDCR) (Address = 0x0091)
Bit(s) Value Description
7:6 00
Disable Quadrature Decoder 2 inputs. Writing a new value to these bits will not
cause Quadrature Decoder 2 to increment or decrement.
01 This bit combination is reserved and should not be used.
10 Quadrature Decoder 2 inputs from Port F bits 3 and 2.
11 Quadrature Decoder 2 inputs from Port F bits 7 and 6.
5 0 Eight bit quadrature decoder counters.
1 Ten bit quadrature decoder counters.
4 This bit is reserved and should be written as zero.
3:2 00
Disable Quadrature Decoder 1 inputs. Writing a new value to these bits will not
cause Quadrature Decoder 1 to increment or decrement.
01 This bit combination is reserved and should not be used.
10 Quadrature Decoder 1 inputs from Port F bits 1 and 0.
11 Quadrature Decoder 1 inputs from Port F bits 5 and 4.
1:0 00 Quadrature Decoder interrupts are disabled.
01 Quadrature Decoder interrupt use Interrupt Priority 1.
10 Quadrature Decoder interrupt use Interrupt Priority 2.
11 Quadrature Decoder interrupt use Interrupt Priority 3.
Table B-29. Quadrature Decoder Count High Register
Quadrature Decoder Count High Register (QDC1HR) (Address = 0x0095)
(QDC2HR) (Address = 0x0097)
Bit(s) Value Description
7:2 read These bits are reserved and will always read as zeros.
1:0 read The current value of bits 9-8 of the Quadrature Decoder counter is reported.
Vue de la page 322
1 2 ... 318 319 320 321 322 323 324 325 326 327 328 ... 348 349

Commentaires sur ces manuels

Pas de commentaire