| 摘要 |
PURPOSE:To easily transfer data from a two-dimensionally arranged memory only by one setting by calculating the sum (or difference) between the value of an address register and that of an address operation register and storing the calculated result in the address register. CONSTITUTION:The DMA controller 12 is provided with an auto-initializing register 13 for setting up the frequency of auto-initializing in each channel, an address operation register 16 to be used for resetting an address at the time of generating auto-initializing and a means for storing the sum or difference between the contents of the registers 14, 16. In case of transferring data from the I/O to the two-dimensionally arranged memory, the transfer of all the data can be attained by setting up the registers 14 and a count register 15 in the DMA controller 12 only once. |
