peb20532 Infineon Technologies Corporation, peb20532 Datasheet - Page 102

• Manufacturer Part Number: peb20532
• Description: 2 Channel Serial Optimized Communication Controller
• Manufacturer: Infineon Technologies Corporation

Figure 48
The RTS
directional flow control. So when the DTE-A’s receiver threshold is reached, the RTS
signal goes inactive ’HIGH’ which is sensed by the DCE and it stops transmitting.
Similarly if the DCE’s receiver threshold is reached, it deactivates the CTS
causes the DTE to stop transmission. These types of DCEs have fairly deep buffers to
ensure that it can continue to receive data from the line even though it is unable to pass
the data to the DTE for short periods of time. Note that a SCC can also be used in the
DCE equipment as shown. Exchange of signals (e.g. RTS to CTS) is necessarily inside
the DCE equipment.
Figure 48
RTS and CTS are used to indicate when the local receiver’s buffer is nearly full. This
alerts the far end transmitter to stop transmission.
The combination of transmitter and receiver out-of-band control features mentioned
above enables data to be exchanged between two devices without software intervention
for flow control.
4.5
4.5.1
Character oriented protocols achieve synchronization between transmitting and
receiving station by means of special SYN characters. Two examples are the
MONOSYNC and IBM’s BISYNC procedures. BISYNC has two starting SYN characters
Data Sheet
DTE A
1) Some MODEMs support bi-directional flow control.
A
shows an SCC as a DTE connected to a DCE (MODEM equipment).
feeds the RTS
BISYNC Protocol Mode
Character Framing
Out-of-Band DTE-DCE Bi-directional Flow Control
SEROCCO-M
CTS
TxD
RxD
RTS
B
input of the DCE (MODEM equipment) that supports bi-
RS232c Signals
(drivers not shown)
TxD
RxD
RTS
CTS
102
DCE
B
Detailed Protocol Description
SEROCCO-M
MODEM
1)
RTS
CTS
TxD
RxD
B
PEB 20532
PEF 20532
(’HIGH’) and
2000-09-14
A