| 摘要 |
<p>PURPOSE:To eliminate the need for setting of a baud rate of a reception data by providing plural start bits to a head of each reception word, measuring a pulse width of plural start bits at the head of each reception word and deciding the baud rate of the word reception based on the pulse width. CONSTITUTION:The transmission of a reception data 23 from an external circuit is started by the trailing of an SRDY signal 21 and a width of an H period among 3 start bits received at first is measured by a start bit pulse width measurement circuit 13 and it is used for a transfer speed of the reception word and a shift clock in matching therewith is generated by a baud rate generator 9 and the remaining reception word is received by a reception shift register 8 from an I/O (SI/O) reception terminal by using a shift clock. In this case, a trailing detection circuit 6 detects the trailing of the first shift clock to reset an SRDY signal latch flip-flop 5 to an H level thereby causing the SRDY signal 21 to H and it is outputted from the SRDY signal output terminal 1.</p> |
