| 摘要 |
<p>PURPOSE:To attain setting of optional communication speed with simple constitution by storing a data selecting a desired communication speed to a rewritable line clock selection circuit so as to switch the speed to a desired communication speed by a communication controller depending on the command of managing table management information. CONSTITUTION:A managing table and control bit consists of flag information of EXTSW EN, DSWEN and SGEN and communication speed information of SG- SPD, H-SPD, M-SPD and L-SPD. For example, when the EXTSW EN-bit of the communication speed management information transferred from a central processing unit 5 is set, a microprocessor 11 discriminates that the EXTSW EN-bit is set, reads the high/medium/low speed of the communication speed combining set information set by an external changeover switch 15 to set the write speed to a communication speed class setting register 17. Then every time the external changeover switch 15 is switched by the operator, it is detected and a data is written into the communication speed class setting register 17.</p> |
