PEB20534H-10 SIEMENS [Siemens Semiconductor Group], PEB20534H-10 Datasheet - Page 166

• Manufacturer Part Number: PEB20534H-10
• Description: DMA Supported Serial Communication Controller with 4 Channels DSCC4
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Semiconductor Group
7.9.2
Similar to the RTS/CTS control for the transmitter, the SCC supports the carrier detect
modem control function for the serial receiver if the Carrier Detect Auto Start (CAS)
function is programmed by setting the ’CAS’ bit in register CCR1. This function is always
available in clock modes 0, 2, 3, 6, 7 via the CD pin. In clock mode 1 the CD function is
not supported. See table 21 for an overview.
If the CAS function is selected, the receiver is enabled and data reception is started when
the CD input is detected to be high. If CD input is set to ‘low’, reception of the current
character (byte) is still completed.
7.10
To provide fast and efficient testing, the SCC can be operated in a test mode by setting
the ’TLP’ bit in register CCR1. The on-chip serial data input and output signals
(TxD,RxD) are connected, generating a local loopback. As a result, the user can perform
a self-test of the SCC.
Figure 60
Note: The transmit data is not disconnected from pin TxD during test loop operation, i.e.
Note: An sufficient clock mode must be used for test loop operation such that receiver
Note: Test loop operation is not supported in high speed channel operation
transmit data is always provided to pin TxD.
and transmitter operate with the same frequencies depending on the clock supply
(e.g. clock mode 2b or 6b).
(clock mode 4).
Carrier Detect (CD) Receiver Control
Local Loop Test Mode
SCC Test Loop
SCC transmit
SCC receive
logic
logic
Serial Communication Controller (SCC) Cores
166
TLP=’0’
TLP=’1’
TxD
RxD
Data Sheet 09.98
PEB 20534