| 摘要 |
PURPOSE:To improve the data transmission efficiency with use of a limited number of transmission buffers by setting a prescribed number of buffers to a transmission buffer number register and stopping temporarily the transmission requests when the number of idle buffers is reduced less than the prescribed number of buffers. CONSTITUTION:A prescribed number B of buffers, e.g., the number of buffers enough to store plural transmission data 20 is set to a transmission buffer number register 5. Then the number N of idle buffers set at an idle buffer number register 4 is compared with the number B of buffers every time the data 20 is stored. If the number N is larger than the number B, the transmission requests are accepted to all data 20. If the number N is equal to or smaller than the number B, a transmission temporary stop request 21a is outputted to a CPU 1 for a logical channel No kept in a transmission waiting state if detected by reference to a control table 11. Then a CPU 1 stops temporarily only the transmission request for the data 20 corresponding to the logical channel. Thus the data transmission efficiency is improved with use of a limited number of transmission buffers. |
