| 摘要 |
PURPOSE:To efficiently perform the print control of a constant pattern by using a DMAC, by providing a means which re-sets a leading address value when a counted value arrives at a final address value. CONSTITUTION:A transfer origin leading address at the initial value register 9, a transfer origin final address at a rotation register 10, a transfer opposite leading address at an initial value register 14, and a transfer opposite final address at a rotation register 15 in the dynamic memory access controller DMAC7 are set from a CPU respectively. The DMAC7 steps address counters 11 and 16 until a CK signal generated by a timer arrives by receiving an RQ signal from the CPU, and sends the content of a memory 3 to an I/O port 4. Comparators 12 and 17 compare the counters 11 and 16 with the registers 10 and 15, and when they coincide, they re-set the leading addresses of the registers 9 and 14 at the counter 11 and 16. Since the data of storage area of a transfer origin is continued to be sent repeatedly to the storage area of a transfer opponent, another processing can be performed with simple constitution, and when the constant pattern is printed repeatedly, print can be performed by using the DMAC. |
