Transmit And Receive Clocking; Figure 6-1. Tx Clock Modes - Comtech EF Data CIM-550 Installation And Operation Manual

CiM-550 IP Enabled Satellite Modem
Theory of Operation
6.3.4 T
RANSMIT AND
TX DATA
TX CLO CK
(TT )
INT ERNAL
CLO CK
(ST )
TX DATA
TX CLOCK
(TT)
TX DATA
TRANSMIT
TX CLOCK
(TT)
INTERFACE
INTERNAL
CLOCK
(ST)
R C
ECEIVE LOCKING
INTERNAL TX CLOCK MODE
TRANSMIT
DATA
INTERFACE
SNTHESIZER
THIS CLOCK IS USED AS THE SYNCHRONIZATION
SOURCE FOR THE EQUIPMENT ATTACHED
TO THE MODEM
EXTERNAL TX CLOCK MODE
TRANSMIT
DATA
INTERFACE
THE MODEM LOCKS ITS CLOCK CIRCUITS
TO THIS CLOCK COMING FROM THE
EXTERNALLY CONNECTED EQUIPMENT
LOOP-TIMED TX CLOCK MODE
TX=RX OR TX<>RX
TX
FIFO
DATA
DIRECT
DIGITAL
SNTHESIZER
THIS CLOCK IS USED AS THE SYNCHRONIZATION
SOURCE FOR THE EQUIPMENT ATTACHED
TO THE MODEM

Figure 6-1. Tx Clock Modes

DATA TO
MODULATOR
CIRCUIT
TX PLL
FIFO CIRCUIT
DIRECT
14.4 MHz
DIGITAL
TCXO
DATA TO
MODULATOR
CIRCUIT
TX PLL
CIRCUIT
FIFO
DATA TO
MODULATOR
CIRCUIT
PLL
CIRCUIT
CLOCK
VCXO
86
CD/CIM550.IOM
CLOCK
VCXO
CLOCK
VCXO
CLOCK
VCXO
PLL
CIRCUIT
RX SYMBOL
CLOCK FROM
DEMOD
Rev. 2