摘要 |
<p>A circuit for driving and receiving signals on a bus line includes a pull-up switch and a pull-down switch. The pull-up switch has an impedance that matches the characteristic impedance of the bus line. The pull-down switch has an impedance of about half of the characteristic impedance of the bus line. When the circuit is receiving a signal or driving a logic high signal on the bus line, the pull-up switch is enabled so that the bus line voltage is pulled up, while the pull-down switch is disabled to prevent the pull-down switch from pulling down the bus line voltage. When the circuit is driving a logic low signal on the bus line, the pull-down switch is enabled so that the bus line voltage is pulled down, while the pull-up switch is disabled to prevent the pull-up switch from pulling up the bus line voltage.</p> |