Toshiba V.90 - Manual (Page 98)

Glossary 79
S-Register: The S-Register stores the parameters for various commands
and modem operations.
synchronous: Having a constant time interval between successive bits,
characters or events. Synchronous data transmission requires both
the sending and receiving devices to use special synchronizing
characters to correct variations in timing between the devices. See
also asynchronous.
T Test function: When normal communication is not possible, this function
checks the modem, personal computer, and telephone lines to
determine if they are normal.
Tone dialing: A dialing method that uses tones instead of pulses to
generate a telephone number. Generally associated with push-button
phones, although some push-button phones can be connected to
pulse lines.
U upload: To send a file to another computer through a modem. See also
download.
UART: Universal Asychronous Receiver Transmitter is the circuit
interface between the modem and computer. It receives serial bit
data from the modem and converts it into bytes for the computer;
and it converts byte data from the computer into bit data for serial
communication.
X XON/XOFF: flow control: A protocol used by devices receiving data. It
uses two signals: transfer ON and transfer OFF. The signals are
controlled by software.