Data transfer device

Abstract

Abstract PURPOSE:To improve the data transfer efficiency by selecting another channel device in consideration of the performance and the characteristic of the peripheral device connected to the channel device and deciding intentionally the data transfer direction in a data transfer state. CONSTITUTION:A priority control circuit PEN 17 transfer the data in the directions shown by a channel device pointed by a channel device number regis ter CHNR 15, a data transfer direction register, and a DIRR 12 respectively in the next clock cycle as long as 1 is set at the bit of a request accepting register RQAR 11 shown by a channel device number of a CHNR 15. When the bit of the RQAR 11 corresponding to the channel device number of the CHNR 15 is equal to 0, the RQAR 11 is checked so as to decide whether another channel device requests the transfer of data or not. If so, the channel device is selected for transfer of data with the priority secured based on the constitution information of the channel device and the state of the data buffer of the channel device. Thus the data transfer efficiency is improved.

Inventors

• 👤 Goichi Komatsu
• 👤 吾一 小松

Bibliographic Details