Zilog Z80180 Manuel d'utilisateur Page 125

  • Télécharger
  • Ajouter à mon manuel
  • Imprimer
  • Page
    / 326
  • Table des matières
  • MARQUE LIVRES
  • Noté. / 5. Basé sur avis des utilisateurs
Vue de la page 124
Z8018x
Family MPU User Manual
110
UM005003-0703
DREQ0 for ASCI transmission and reception respectively. To initiate
memory to/from ASCI DMA transfer, perform the following operations:
1. Load the source and destination addresses into SAR0 and DAR0
Specify the I/O (ASCI) address as follows:
a. Bits A0–A7 must contain the address of the ASCI channel
transmitter or receiver (I/O addresses
6H-9H).
b. Bits A8–A15 must equal 0.
c. Bits SAR17–SAR16 must be set according to Table 16 to enable
use of the appropriate ASCI status bit as an internal DMA
request.
Table 16. DMA Transfer Request
SAR18 SAR17 SAR16 DMA Transfer Request
X00
DREQ0
X 0 1 RDRF (ASCI channel 0)
X 1 0 RDRF (ASCI channel 1)
X 1 1 Reserved
Note: X = Don’t care
DAR18 DAR17 DAR16 DMA Transfer Request
X00
DREQ0
X 0 1 TDRE (ASCI channel O)
X 1 0 TDRE (ASCI channel 1)
X 1 1 Reserved
Note: X = Don’t care
Vue de la page 124
1 2 ... 120 121 122 123 124 125 126 127 128 129 130 ... 325 326

Commentaires sur ces manuels

Pas de commentaire