SSCI HSS4NG, User Manual, Page: 23 / 34

CCII/HSS8/6-MAN/004 2009-08-31 Issue 1.2
CH8MAN04.WPD
Page 15 of 26
5.5.1 HDLC Protocol Information Members
Name Options Description
Baud Rate
1 200 - 1 Mbit/s (RS-232)
1 200 - 16 Mbit/s (RS-422/485)
Any values permissible.
The equation to calculate the actual baud rate for FM0/1,
Manchester and Diff. Manchester is as follows :
Actual baud rate = 100 MHz / 16 / ROUND (100 MHz
/ 16 / Desired baud rate)
The equation to calculate the actual baud rate for NRZ/NRZI is
as follows :
Actual baud rate = 100 MHz / ROUND (100 MHz /
Desired baud rate)
Where ROUND () implies that the result is rounded to the
nearest integer.
Used to specify a single baud rate for
both transmitter and receiver.
Units in bit/s.
Clock Source CLOCK_DEFAULT C L O C K _ D E F A U L T c o n n e c t s
BRGs [1 - 4] to Ports [1 - 4] and
Ports [5 - 8].
For NRZ/NRZI :
When transmit clock is set to
CLOCK_BRG [1-4], then receive
clock is still set to CLOCK_EXT[1-4]
for Ports [1 - 4] and [5 - 8].
For FM0/1, Manchester and Diff.
Manchester :
Transmit and receive clocks can be
set to one of CLOCK_BRG [1 - 4] or
CLOCK_EXT[1-4].
Note :
There are four BRGs and four clock
input pins per PowerQUICC II
processor.
CLOCK_BRG1
CLOCK_BRG2
CLOCK_BRG3
CLOCK_BRG4 BRG [1 - 4]
BRG1 for Ports [1 and 5]
BRG2 for Ports [2 and 6]
BRG3 for Ports [3 and 7]
BRG4 for Ports [4 and 8]
CLOCK_EXT1
CLOCK_EXT2
CLOCK_EXT3
CLOCK_EXT4 External Clocks connected on
CLK_IN Pins.
Note :
CLOCK_EXT[1-2] can only be
used for Ports [1 and 2] and
[ 5 a n d 6 ] , w h i l e
CLOCK_EXT[3-4] can only be
used for Ports [3 and 4] and
[7 and 8].
CRC Mode 16-bit
32-bit HDLC CRC mode.
Diagnostics Mode
NORMAL Normal operation. Use this for
external loopback .
Set diagnostic mode.
External loopback - RS-422/485 :
Connect TxD+ to RxD+, TxD- to
RxD-, ( to and
CLK_OUT- to CLK_IN- for
synchronous mode).
External loopback - RS-232 :
Connect TxD to RxD, (CLK_OUT to
CLK_IN for synchronous mode) and
RTS to CTS and CD.
Set diagnostic mode.
For synchronous mode :
see
encoding_method .
LOOPBACK
Internal loopback :
TxD and RxD are connected
internally. The value on RxD,
CTS and CD is ignored. The
transmitter and receiver share
the same clock source.
ECHO The transmitter automatically
resends received data bit-by-
bit.
LOOPBACK_ECHO Loopback and echo operation
occur simultaneously.